"Jump Into the Fire" (Harry Nilsson)

Quirky is probably the best way to describe the late Harry Nilsson.  How else could you characterize someone who had both a heartfelt ABC-TV children's special and a raunchy rock song containing the line "I sang my balls off for you, baby" to his credit?
If the name Harry Nilsson doesn't mean much to you, let me fill you in; he's actually a pretty interesting character with a rollercoaster of a life.
When he was barely three years old, his father abandoned his family, leaving Harry, his half-sister, and his mom to fend for themselves in the hard knocks Bushwick neighborhood of Brooklyn.  (They occasionally ate dog food when times were exceptionally tough.)  In time, the fractured family wound up in Southern California, where Nilsson eventually dropped out of high school in 9th grade but landed a job as a banker in LA by fibbing about his education.  While working at the bank by night, he was working to break into the music industry by day—recording scratch vocals for demos, rubbing elbows with various producers/arrangers, and plugging his own songs to whomever would listen.  Eventually, he landed a recording contract with RCA Records, and his first album, Pandemonium Shadow Show (1967), ended up grabbing the attention of the Beatles' publicist Derek Taylor and, ultimately, Paul McCartney and John Lennon, who became major proponents of his work. 
By the time the early 70s rolled around, Nilsson was hanging out and making music with Lennon and Ringo Starr—that is, when they weren't enabling each other's addictions and partying like...well, rockstars.  For a number of years, the trio became almost more well known for their carousing than their music.  (Case in point: there was an infamous incident where Nilsson and Lennon got stinking drunk and ended up getting thrown out of an LA comedy club after mercilessly heckling the Smothers Brothers.)  
Somehow in the midst of all the partying, Nilsson created a bizarre pop gem called Nilsson Schmilsson (1971) with producer Richard Perry at the helm.  There's everything from strange Calypso (the notorious "Coconut") and power ballads (the schmaltzy, albeit impeccably sung, "Without You") to screaming proto-punk, which brings us to the song at hand: "Jump Into the Fire."
Much like the material on his buddy's 1970 album, John Lennon/Plastic Ono Band, "Jump Into the Fire" rocks a spare groove (with zero chord changes) and minimal instrumentation: couple of guitars, thunderous drums, pounding barrelhouse piano, and funky electric bass. And, ohh!  That bass...
Session musician Herbie Flowers takes a three-note line that could have been mundane and utterly forgettable and turns it into something debauched and decadent by sliding into the tonic at the start of each measure.  It's so perfect and indelible that it easily becomes the hook of the song.
If that weren't enough, he takes it a step further by detuning during the frenetic, tom-tom heavy drum solo (performed by Jim Gordon of Derek and The Dominos fame).  Supposedly, Flowers was just screwing around, figuring that Perry would just cut the jam short and edit out the farcical descending notes when all was said and done.  Instead, his goofing became the song's second signature.