A drunken wager based on the Arrangement between Aziraphale and Crowley leads to friendly competition...which could place the angel in a very bad situation indeed.
Whenever Aziraphale tried to remember how he'd got himself into such a mess, he could never quite recall. They'd been at a London pub, he remembered that. Brandy had been involved. And rum. And gin. And some of that odd liquor made from potatoes. Well, really, how could you go wrong, drinking something as nutritious as potatoes?
And then Crowley had brought up music.
"Music o' the seph--spears--spheres, y'mean?" Aziraphale had slurred, fumbling for a bottle of claret and very nearly knocking it over.
Crowley had fired a bleary yellow glare in the angel's direction. "No. Real music. Human music. The kind you can dance to."
Aziraphale looked bewildered. "You mean like Elgar or Liszt? Or something more like this?" In a clear, pure tenor, he began to sing, "Oh, don't deceive me, oh, never leave me--"
Crowley's face seemed to have turned a peculiar shade of purple. "For G--for Sa--for someone's sake, could you stop singing that song? It was written in 1513! It's four hundred and seventeen years old!"
"So wha'?" muttered Aziraphale. "'S still good music."
"Nothing," retorted Crowley. "Not if you don't mind wailing for thirty-five verses or so that you've been deceived, used and abandoned by someone you trusted. It's not only outdated--it's the song of the eternal victim."
A blurred thought staggered into Aziraphale's mind: that it was understandable for Crowley to dislike being reminded of his deceitful, demonic nature. Aziraphale couldn't quite work out if that was a sign of corruption or redemption.
Best to stick to the basics. "You said music /I /could dance to."
"I did not!"
"Did so. You said, 'The kind you can dance to.' I heard it, loud as anything."
"Oh." Crowley looked disgruntled. "Well, that was a genny...genial...GENERIC statement. 'You' meaning everyone. Not you-Aziraphale."
"Still doesn' matter. There's no music that ev'ryone danshes--dances--to. Pract'ly no angels dance."
He hadn't realised--not then--that the demon had suddenly sat up very straight, or that his serpentine eyes were far less bleary than before. "You dance. I've seen you."
Aziraphale was beginning to feel sleepy. "Was g'd at gavotting. Once. Wen' out of style. 'N' you're a demon. Demons don' dance. Not well, 'nyway."
Crowley snorted, a distinctly uncelestial sound that made Aziraphale's head ache. "I bet if I found some dance music--modern music, mind--I'd dance better than you."
"Rubbish." Aziraphale considered for a few minutes and then added, with as much righteousness as he could manage at the moment, " 'N' we're not s'pposed t' gamble."
"Oh, come on," wheedled the demon. "Just a little bet. Something to help us both out."
Aziraphale glanced up at Crowley. There seemed to be at least six of him. Three of the Crowleys were spinning around in slow, lazy circles. He closed his eyes and took several deep breaths. "No," he said faintly. "Don' wanna. You're a demon. You'll cheat."
Even in his inebriated state, Aziraphale noticed the demon pull back at that. "That's not fair, angel." Crowley's voice was soft and sounded genuinely hurt. "I don't cheat...well, not you. Most of the time, anyway."
"Not on purpose," Aziraphale slurred. "Jus' automatically using diabolic powers. Y'couldn't help it."
"Is...that...so?" Crowley drawled, a faintly sibilant echo creeping into his voice. "What about this, then? If I win, you have to help me out for a week. Two evil deeds for every one good one. And if you win, I have to help you for a week. Two good deeds for every evil one. That's fair, isn't it? No diabolic or angelic powers allowed. First one to use supernatural powers to win loses. Does that sound reasonable?"
Aziraphale pondered that. A bet on the Arrangement did sound reasonable, when Crowley put it that way. Almost--righteous.
And besides, it would be such fun to compel Crowley to give in to his naturally good impulses when he, Aziraphale, won.
"A'right. I 'ccept."
The angel leaned back sleepily in his chair. The last thing he saw before dozing off was the demon's delighted smile.
Crowley hadn't mentioned the bet for several weeks after that. Aziraphale had almost  convinced himself that it was an alcohol-induced hallucination, and had firmly resolved to never drink those mixed drinks with weird names again. He really should have known better than to drink something called a Salty Dog or a Rusty Nail. From now on, he was going to stick to drinking natural stuff. Like orange juice. And potatoes.
Then Crowley had rung him up at his bookstore. "Hello, Aziraphale. Ready to settle our bet?"
"B-bet?" For a moment, Aziraphale didn't know what Crowley was talking about. Then memories of the pub--and that stupid drunken wager--seeped back into his conscious mind, and he very nearly swore.
There was utter silence on the other end of the telephone.
"Er--Crowley? Are you there?"
"Yeah. Just giving you a chance to recollect your thoughts."
"Don't say 'yeah,' my dear," Aziraphale said, correcting Crowley automatically. "It's vulgar. And so American."
"But appropriate, since that's where we're going."
"We're going to America?" Aziraphale sat down with a thump in a Duncan Phyfe chair that had just materialised behind him. Good heavens, he thought miserably. Can this day get any worse?
He could almost hear Crowley smirking over the line. "Oh, we certainly are. Better close up shop now, angel--it's a long flight across the Atlantic, and I don't want you pleading total exhaustion when we get there. Exhaustion really would not do for what I have in mind. At least--not at first." Crowley laughed, a low, dirty chuckle filled with amusement and malice.
Aziraphale wet his lips and swallowed twice. "Er--you know, on second thought, Crowley, I don't think my people would approve of my making a bet with you." It was weak, hopelessly weak, but he hoped that Crowley would go for it.
"For that matter, I doubt if either your people or mine would officially approve of the Arrangement," retorted Crowley. "Anyway, approval doesn't matter at this stage. You made a bet with the devil--or a demon, anyway. You weasel out, I win by default. Those are the rules."
Yes. Aziraphale knew that was true.
"And I'd hate to win that way," continued Crowley in a sardonic tone. "Winning because I'm a demon--why, that would be almost like cheating, wouldn't it?"
Aziraphale winced. "Look here, Crowley, I'm--"
"Save it. I'll be at the bookshop in an hour. Be ready to fly."
The voice on the other end of the wire was wary. "Yes?"
"Er--could you please tell me where we're going? America's a big place."
"Chicago." And Crowley rang off.
Aziraphale hung up the receiver quietly. "Chicago?" he implored the empty air. "Why Chicago?"
Crowley refused to tell him anything on the flight over. Instead, the demon flew majestically westward, doing an excellent imitation of the angel of silence. Except for the smug glint in his eyes and the occasional sly glance at Aziraphale, that is.
Aziraphale, for his part, tried to be celestially contemplative, offering benedictions and laudations to the Almighty and ignoring the bloody annoying Crowley. This worked until he realised that Crowley was ignoring Aziraphale ignoring him.
After a non-stop flight (which left Aziraphale with a sore back and aching wings) and a great many out-of-the-way detours due to bad weather and turbulence (which left him with a conviction that Crowley had invented a new form of evil especially for those who flew), the two landed in an alley outside of a short, squat building of brick and steel. It looked, in Aziraphale's eyes, like a primitive temple, only much uglier.
"Well?" he said a trifle testily. "What now?"
Crowley stretched languorously as a charcoal-coloured linen suit--complete with a jacket with long, broad lapels, square shoulders and ventless tails, and generously-cut long trousers--manifested around him. With a snap of his fingers, wraparound sunglasses  emerged from his eyes.
"We're going in there." He pointed at the squat temple. "Better get dressed. And no tweed."
Aziraphale sighed, and thought a brown herringbone wool suit around himself.
Crowley surveyed him, then shrugged. "Not what I would have chosen, but it's your funeral. Come along." He strode out of the alley, the angel hurrying after him.
Aziraphale quite determinedly said nothing until they drew near the door. That's when he saw the sign:
MERRY GARDEN DANCE HALL
DANCE MARATHON STARTS AT 6:00 P.M.
"A dance marathon?" he asked incredulously.
Crowley nodded. "You wouldn't believe how hard it was to find one that accepted solo dancers. Most of these things are for couples only."
"Solo--" Aziraphale stared at Crowley. "You're not serious, my dear."
Crowley flashed a dangerous smile at Aziraphale, then stepped up to the hostess, who was checking reservations. "I'm here for the dance marathon. So's my friend. The names are Anthony Crowley and Ozzie Rafale."
The girl smiled dazzlingly at Crowley, handed each of them a number (13 for Crowley, 87 for Aziraphale ) and motioned both of them toward the sidelines of the dance floor.
As he followed Crowley in, Aziraphale noticed the tense, desperately determined faces of his mortal competitors. Most were young; none were more than middle-aged. Almost all were in pairs, though, some, like Crowley and himself, didn't have any partners with them. And there was one more thing about the mortals that troubled Aziraphale.
"They look hungry," he whispered to Crowley.
He could tell from the demon's exasperated sigh that Crowley was rolling his eyes. "Aziraphale. In case you haven't noticed, there's a worldwide depression. The New York stock market crashed last October. Banks have collapsed. Life savings have been lost. People are out of work, and there are no jobs to be had. Of course they're hungry."
"Then why are they here?"
Another exasperated sigh. "For the cash prizes. Thousands, for the winner."
Aziraphale frowned. "Look here, Crowley, I don't think I can do this. Competing against starving people--it's very unangelic."
Crowley pondered for a minute. "Well, I don't see what difference it makes. It's not as if you're going to win anyway."
Aziraphale bristled. "Really!"
"And even if you did," said Crowley, as he hung his number around his neck and motioned Aziraphale to don his as well, "you'd just give the money to charity, right? Or to one of the deserving young couples here."
It seemed to Aziraphale that there was something wrong with Crowley's logic, but for the life of him, he couldn't figure out what it was. "Well. Er. Yes. I suppose so."
"So you don't really have to worry about being unangelic, do you?" concluded Crowley smugly. "The only thing you have to worry about is losing."
Aziraphale glared at Crowley, radiating virtuous wrath.
"Oh, and forget about using celestial grace so that you can win and give the prize to the deserving. That'd be cheating--and under the terms of the bet, the first one who cheats loses. Understand?"
Whatever the angel might have said next was drowned out by the voice of the emcee explaining the rules. The rules were very simple: dancing, aside from the thirty-second breaks between songs, had to be continuous. There were breaks, if you wanted to call them that--fifteen minutes rest every four hours. And if anyone stopped dancing at any other time, he or she was out of the contest for good.
Aziraphale turned horrified eyes toward Crowley. "Crowley, this is cruel. These poor, half-starved children--they'll never survive it!"
"Miracle them some stamina, then," said Crowley absent-mindedly, then flushed, grimacing as if biting his tongue.
Aziraphale folded his arms across his chest and scowled at the demon. "No using supernatural powers, you said. First person to use them loses the wager."
"I said no using supernatural powers to win," Crowley corrected. "A few minor miracles to help the mortals keep up with us--well, it's not something my people care about, but if it keeps you focused on what's important, I'm willing to go along with it. It's not as if we haven't done each other's jobs before." He gazed heavenward, wearing a martyred expression.
"That's not the point," muttered Aziraphale.
"No," replied Crowley agreeably, as loud brassy music began playing. "The point is, the band's started and you have ten seconds to get on the dance floor." He grabbed hold of Aziraphale's hand, took two steps, and released the angel's hand. "There. Now, DANCE!"
With that, he slipped away into the crowd and was lost from view.
Aziraphale stared helplessly at the crowd of rapidly gyrating dancers, gritted his teeth and began to do a partnerless gavotte.
By the eighth day of the dance marathon, the organisers were starting to feel that something odd was going on. There hadn't been a report of a single blister or pair of worn-out shoes. All the contestants were well fed and well rested. The dancing hadn't slowed to an exhausted walk. Not a single person had dropped out (or, more to the point, dropped dead ). It was all quite disturbing.
By the tenth day, Aziraphale had wearied of dancing the gavotte by himself. This might have had something to do with the fact that he had kissed a burly stevedore who didn't realise and didn't care that gavotters were supposed to kiss everyone in the room. 
By the twelfth day, Aziraphale was rather frantically trying to combine steps from the gavotte with steps the mortal dancers were doing. Nevertheless, he was quite certain that no one had noticed his lack of skill--how could they? After all, he didn't look any more ridiculous than any other dancer.
And on the thirteenth day, he noticed Crowley.
Crowley, unlike Aziraphale, wasn't dancing alone. A young couple was on either side of him, and he was alternating dancing with the lovely redhead from the left-hand couple and the cute blonde from the right-hand one. Swing and grab the redhead, two slow, sinuous steps, swing the redhead back into her partner's arms, two quick, gliding steps (one foot back, one in place), grab the blonde, a step to the side, shuffle, shuffle, swing the blonde back into her partner's arms, repeat. All executed with absolutely flawless, sensual grace that would have made every choreographer on Broadway and in the West End bite his shoes in half from sheer frustration.
Crowley glanced in his direction and smiled wickedly.
Somehow, Aziraphale managed to keep his feet moving, despite the fact that the room, inexplicably, had suddenly become immensely hot.
All right, he thought to himself. If that's what it takes, that's what I'll do.
And that was when the contest really began.
On the twentieth day, Aziraphale thought that he was mimicking the dances the mortal contestants were doing quite well, even though it was dashed difficult to jitterbug or do the Charleston without a partner. Especially if you'd never bothered to learn the dances before now.
One the twenty-first day, Crowley added a few acrobatic flips to his version of the jitterbug.
On the twenty-third day, Aziraphale noticed that some of the pudginess that had accumulated from more than a century of eating cream buns and trifle for elevenses had begun to melt away.
On the thirtieth day, Crowley improvised a circle dance based on the Lindy Hop that inspired a couple from South Carolina to create a brand-new dance when they got home. 
On the fortieth day, Aziraphale managed to show off for Crowley. Well, not quite show off, as angels don't do that sort of thing, or at least don't admit to doing it. Aziraphale, however, not only did a faultless version of the Lindy Hop, he also twirled a young lady out of the arms of her escort and danced a few brief steps of the most graceful--and the most ethereal--tango the world had ever seen.
By the sixtieth day, Crowley had introduced those present to his version of the rumba and samba, Aziraphale had done all in his power to restore the Charleston to white-hot popularity, and the organisers were beginning to worry that the marathon would last unto eternity.
And on the eighty-fifth day, while on one of the all-too-short breaks, Aziraphale overheard part of a conversation.
One moment, he had been sitting on a bench leaning against the dance hall's wall. Crowley was beside him, lounging against the wall so lazily that it was almost an offensive act. Both of them were aiding the other contestants, though Crowley swore that help was the furthest thing from his mind.
"I just don't want you to get distracted by fussing over the humans," Crowley told Aziraphale in a low tone, automatically healing bleeding feet, as well as various fractures of toes and ankles. "If I thought it would make you pay more attention to your dancing and less to the mortals, I'd--"
The band--which had likewise gone on break a few minutes earlier--burst into a chaotic cacophony.
Crowley turned porridge-colour and stood up very straight. "Yes, Lord," he said softly, clenching his fists so tightly that his nails sliced open his palms.
The cacophony blared again. Aziraphale huddled on the bench, trying to keep very still. It would never do for the Lords of Hell to learn that an angel was inadvertently eavesdropping on their private counsels--even if he couldn't understand a word that was being said.
Crowley's eyes flickered in Aziraphale's direction. "No. He's not here. Went to get a sweet during the break."
More noise, this with a more insistent tone.
"Of course I'm sure," Crowley replied tensely. "Why wouldn't I be?"
A long, discordant clamour fairly shouted itself at Crowley.
"Doing the best I can, Lord, but--well, this is a fairly tricky assignment--"
A veritable roar.
"Of course I'm making an effort! Really keen on helping the old firm, you know me--no, I DON'T want this assignment to go to Hastur and Ligur--"
A metallic snarl.
Crowley glared toward the band. "I am doing everything in my power to ensure that this assignment ends as it should," he said stiffly. "Will that be all?"
Apparently, that was all, for the discordant, agonising noise vanished and was replaced by normal band music. Aziraphale, Crowley and perhaps one-third of the contestants straggled back onto the dance floor. The other two-thirds, who hadn't been healed during the break, glared at them with icy eyes.
"You didn't tell me you were here on assignment," whispered Aziraphale reprovingly.
"Must have slipped my mind," said Crowley, slithering away into the crowd.
Scowling and trying to think angelic thoughts, Aziraphale began to dance. Honestly, what HAD got into the demon lately? First he insisted on coming to America, of all places, to settle some pointless bet. And then making him dance for days, persuading him to perform minor miracles just to keep the other contestants going, not telling Aziraphale that he was on assignment, shutting him out when Aziraphale asked him about it...it was disturbing.
And he didn't even want to think about why Hell had made such a point of contacting Crowley.
The fun had gone out of the competition.
The eighty-fifth day wore into the eighty-sixth. Aziraphale didn't notice that mortal contestants, deprived of the stamina and health that he and Crowley had been supplying until now, were drifting to the sidelines. He just wanted this to be over.
Then, at close to midnight on the eighty-sixth day, a young woman collapsed, falling onto Aziraphale and pinning him to the floor.
No one so much as raised an eyebrow at the tangle of contestants on the floor, or at the young man--little more than a boy, really--trying frantically and unsuccessfully to pull his partner to her feet. The organisers offered hallelujahs that the contest finally seemed to be ending; the band continued to play; the contestants continued to dance.
All, that is, but Crowley, who hastened over to the distraught young man and the squashed angel.
"Are you all right?"
"N-no," stammered the young man. "She's not breathing. I don't know what's wrong, but I can't get her to breathe!"
Aziraphale heard Crowley mutter something about hanging sheep as he snapped his fingers. As the girl inhaled, the young man helped her to her feet, then gazed at Crowley with shining eyes.
"Thank you, doctor." The young man hugged his girl tightly. "I don't know how you knew what to give her, but...well, any time you need something from me, just ask. I owe you."
"No," said Crowley firmly, as he pulled Aziraphale to his feet. "You really don't." He glanced at the angel. "Come along, Ozzie. Time to clear the dance floor. The contest is over for us."
Aziraphale waited until they were well outside and out of mortal earshot before speaking. "That was decent of you, giving your assignment another chance like that."
Crowley grimaced at the word 'decent'. "He wasn't my assignment. Neither was the girl."
Aziraphale thought back. It had to be one of those wretched girls Crowley'd been jitterbugging with. Or maybe both. "Did you--er--succeed?" he asked, unable to keep the disapproval from his voice.
Crowley's tone was unreadable. "Maybe."
Well. That told him exactly nothing. Obviously Crowley was still in A Mood. Aziraphale elected to shut up.
After walking silently for several long blocks (during which Aziraphale wondered why they hadn't just headed back to the alley, dematerialised their clothes and flown home--er, back to England), Crowley spoke up.
"You did a good job, dancing," he said grudgingly. "I didn't think you had it in you."
Aziraphale sighed. If Crowley could be semi-gracious, he supposed he could as well. "You were better. Far better. And I stopped first, so automatically I lost."
Crowley shook his head solemnly. "No. You didn't lose."
"Yes. I did." The angel made an unpleasant face; he hated having to do evil deeds, Arrangement or no Arrangement. Still, fair was fair. "What do you need help on this time, Crowley?"
Crowley stared at him over the tops of his sunglasses. "You don't get it, do you?"
Crowley leaned toward the angel swiftly, like a cobra about to strike. He spoke in a frighteningly patient voice. "You made a bet with the forces of evil. Two evil deeds for every good one. No other limits. Now, if you lost the bet, as you say you did, then there is nothing to stop me from telling you to renounce Heaven and swear eternal loyalty to Hell, is there? That's two evil deeds, as per the terms of the bet."
Aziraphale gulped. It was true--wagers with demons, and the outcomes of those wagers, did have the force of law. If the bet didn't have sharply defined limits, a demon could make you do anything if you lost. Heaven didn't intervene, in such cases. It only promised deliverance from evil, not deliverance from stupidity.
And he had lost.
"Er--you wouldn't do that, though...would you?" he implored the demon standing in front of him.
Crowley glanced at Aziraphale in exasperation. "Of course not. You think I want to start breaking in a new angel after all these years? Spend a couple of millennia getting him used to the idea of the Arrangement? Dealing with you as a real enemy? I don't think you'd exactly thank me for making you Fall."
Aziraphale rubbed his chin in puzzlement. "Then why go to all this trouble?" A scrap of the half-understood conversation between Crowley and Hell flitted across his mind. "Hastur. Ligur."
Crowley suddenly found the stars infinitely fascinating. "Yeah. One of the waiters at that pub we were at belongs to them--don't ask me how, I didn't delve into gruesome details. He reported that drunken bet we made.
"Next thing I knew, Dagon had contacted me at my flat. He demanded that I follow through. Said I could probably count on a promotion if I could manipulate an angel into Falling--and if I wouldn't do it, well, Hastur and Ligur would just love to take one of your lot down. I only got first crack at you because I'd made the bet to begin with."
Aziraphale glared at his demonic companion. "Really, dear boy, you could have told me!"
Crowley shook his head as he continued to stare at the stars. "No. That would have invalidated the bet. I'd have been cheating on your behalf. We would have both lost, that way. There are /rules/."
The angel turned a grief-stricken face toward Crowley. "I still lost."
Crowley grinned at Aziraphale. "Nope."
Aziraphale frowned. "How do you figure that?"
"Well, traditionally, in bets with demons, the demon gets to determine who won. I say that you were quite good and that there wasn't a hairs-breadth difference in skill--though there was certainly was in style. And I say that we both stopped at exactly the same moment, me because I heard a young woman falling over, and you because the same young woman fell on top of you. Equal skill, same stopping time...sounds like a tie to me."
The angel stared at the demon. "They'll NEVER let you get away with that."
"I'm a very good liar," Crowley pointed out cheerfully. "I should be, after nearly six thousand years. And it's hardly my fault, is it, that a clever and perceptive enemy caught on to what I was doing and thwarted me with celestial skill?"
"Hastur and Ligur will never accept that," said Aziraphale after a long pause.
"No. But Dagon and the higher-ups will. Less paperwork. And it's easier than believing the truth."
"And what is the truth, Crowley?" Aziraphale asked gently.
"The truth is," said Crowley deliberately, "that the next time we get drunk and make a bet with each other, we should gamble something unimportant. Like matchboxes. Or money. Something that won't cost either of us anything."
"And no more dance marathons." Aziraphale rubbed his left leg vigorously. "From now on, let's stick to something sedentary. Like mah-jongg. Or crossword puzzles. Or Snap."
"Sounds good to me." Crowley banished his clothes with a thought, stretched glossy black wings to the sky and then turned to Aziraphale.
"Come on, angel," he said softly. "Let's go home."
 The song is called "Early One Morning," and is one of the oldest love songs in English. Reportedly, it does trace back as far as 1513. Aziraphale was singing the chorus. Here's the Sarah Brightman version of the song:
Early one morning, just as the sun was rising,
I heard a maid singing in the valley below;
"O don't deceive me,
O do not leave me!
How could you use a poor maiden so?"
"O gay is the garland, fresh are the roses
I've culled from the garden to bind on thy brow.
O don't deceive me,
O do not leave me!
How could you use a poor maiden so?"
"Remember the vows that you made to your Mary,
Remember the bow'r where you vow'd to be true;
O don't deceive me,
O never leave me!
How could you use a poor maiden so?"
Thus sung the poor maiden, her sorrow bewailing,
Thus sung the poor maiden in the valley below;
"O don't deceive me,
O do not leave me!
How could you use a poor maiden so?"
A song about a pure and honourable person being tragically betrayed by a deceitful liar--well, it's really not the ideal song for an angel to be singing to a friend who happens to be a demon.
 Of course, being an angel, Aziraphale couldn't lie to himself and believe it as a human could, but he had mastered the fine art of not thinking about a topic more than was strictly necessary.
 Wraparound sunglasses hadn't been invented yet, of course, but Crowley was of the opinion that anachronisms could be ignored in favour of style any day of the week.
 Eighty-seven being the number assigned, in gematria, to, among other things, the word avodah (worship) and God's description of Himself: "I am the Lord." Hebrew letters, in ancient times, doubled as numbers (aleph = 1, bet or beth = 2, etc.). Gematria is a kind of numerology Jewish scholars used, particularly in the Middle Ages, to reveal hidden meanings in the Bible, the Torah and the Talmud. If either Aziraphale or Crowley noted the numeric symbolism, they tacitly agreed not to mention it.
 Something many unscrupulous organisers of dance marathons counted on, since dead contestants, unlike live ones, didn't collect prizes.
 Aziraphale altered the man's memory slightly, but it was a very near thing.
 The dance later became known as the Big Apple, after the Charleston, S.C. dance club that the couple frequented. Crowley was rather tickled later when he learned that he had inspired a song that was named after apples.
 He would have been astonished and gratified if anyone had told him that he had done a flawless job, and to learn that what he had done was called the tango.
Oh, and there really was a dance marathon at the Merry Garden Dance Hall in Chicago on May 26, 1930. It was one of the few dance marathons not listed as having been a couples-only or a solo-dancers-only dance; I took that to mean that it had accepted both couples and soloists, particularly since it was the largest marathon in Chicago in the 1930s. Large marathons often did accept both. The actual marathon ran for 2080 hours--more than 86 days. It's not the record for a dance marathon--but it's close.