"Stayin' Alive" (The Bee Gees)

I'd venture that no track is more associated with disco than "Stayin' Alive."  I hear that genuinely funky guitar riff, and I can't help but picture John Travolta strutting down the sidewalk with his paint can like the Prince of Bensonhurst.
A little history: British music journalist Nik Cohn wrote an article for New York Magazine in June 1976 called "Tribal Rights of the New Saturday Night."  It was a snapshot of working-class kids in New York's outer boroughs and the "disco culture" they had coopted from black kids and reshaped in their own polyester/fuhgeddaboudit image.  Turned out, the article was a work of fiction.  But that didn't stop film producer Alan Carr and Robert Stigwood, owner of RSO Records (home of The Bee Gees), from snapping up the film rights and turning it into Saturday Night Fever (1977).  
So when it came time to record a soundtrack for the film, Stigwood naturally tapped the Brothers Gibb.  They already were riding high on a newfound wave of popularity, having shed their image as 60s balladeers and reinvented themselves as pop-R&B stars, tapping into their love of Philly soul (think: The Stylistics, The Spinners, The O'Jays) and brother Barry's distinctive/semi-creepy falsetto.
Long story short, the band recorded the track "Night Fever" first, thinking it would be the soundtrack's centerpiece.  The film execs at Paramount didn't agree, so the group immediately went to work on a song that Barry had written about a working class guy who escapes the gloom of 70s New York by going dancing (in other words, the entire plot of the movie).
Right at the start of the sessions, their drummer's father died.  When he flew home to be with his family in England, they were without a rhythm section.  So record producers Albhy Galuten and Karl Richardson took a two-second clip of the drums from "Night Fever" and created a loop (this is 1977, remember; we're talking literal loop of tape that was 22 feet long and stretched around the recording studio) to serve as the rhythm track for the song.  (A little in-joke between the band and producers, the liner notes of the soundtrack credit "Bernard Lupé" as the drummer on the track.)
Anyway, I'll never forget hearing the song on my parents' record player as a little kid, feeling the heartbeat thud of those drums and soaking in that chant-like chorus while watching my mom and dad trying to remember the steps to "The Hustle"—a small (and rare) glimpse into their dating life, pre-marriage and pre-me.
For better or worse, it's a time capsule of its era for anyone who was around to remember it.