"Walk on the Wild Side" (Lou Reed)

Quite honestly, I didn't know what to make of "Walk on the Wild Side" from Transformer (1972) the first time I heard it as a pre-teen. At the time, I knew little or nothing about Lou Reed or the Velvets, so I had no clue the song was about actual people who were associated with Andy Warhol and his so-called Factory. I mean, even in context, it's still pretty peculiar: a jazz-inflected R&B song with half-spoken/half-sung vocals about transvestites and hustlers.
As Reed notes in this clip from the Classic Albums series, he'd been approached about turning Nelson Algren's gritty 1956 novel A Walk on the Wild Side into a musical.  So he composed a title song, only to have the writing team abandon the play for a different project. Reed had a song without a home, so he reworked it as a chronicle of the real-life characters he'd encountered at Warhol's Factory: Holly Woodlawn, Candy Darling, Joe Dallesandro, Joe "Sugar Plum Fairy" Campbell, and Jackie Curtis.
Despite knowing that those are/were real people, it didn't really sink in until I got the chance recently to visit Pittsburgh's Andy Warhol Museum, where there are numerous photographs (and occasionally videos) on display of those very folks. I got a pretty good sense of what life at Warhol's Union Square (NY) studio must have been like in the late 60s: a non-stop carnival of misfits looking for their place in the sun, shelter from the elements, or other misfits like themselves. And as much as they were parasites, trying to suck fame and sustenance from Warhol's very veins, they were his family, too. Strip away the campiness and glam of Warhol's photos of this brood, and there's an unmistakeable tenderness.
That's why, when I hear the strings swell behind Herbie Flowers's double-tracked bassline and the Thunderthighs singing their doo-do-doo-do-doo-do-do-doo's before that after-hours sax kicks in, I sense endearment behind the seediness now.
There's no judgment. No finger-wagging. It's just poetic honesty about some unconventional souls Reed once knew.

"Melody" (Serge Gainsbourg)

French pop artist Serge Gainsbourg was never a stranger to controversy or pushing buttons.  Case in point: his steamy 1969 single "Je t'aime...moi non plus" with his then-girlfriend, British actress Jane Birkin, which replicated a conversation between lovers in the middle of getting it on, complete with audio vérité moans to ratchet up the realism.  (In the European countries where the single wasn't banned outright, it was a massive hit.)
Which brings us to the song at hand: "Melody" off the 1969 concept album Histoire de Melody Nelson.  In the album's brief 7-song cycle, Gainsbourg tells the story of a questionable love affair with a 15-year-old expat named Melody Nelson.  In "Melody," the story begins with Gainsbourg tooling around in his Rolls Royce at night, mired in his own thoughts, when he accidentally collides with Melody as she's riding her bicycle.  He rescues her and a steamy affair ensues, with Gainsbourg creepily declaring at the end of the track, Melody Nelson a les cheveux rouges / Et c'est leur couleur naturelle (translated: Melody Nelson is a natural redhead).
I'll say this: Gainsbourg's dirtbag proclivities leave me cold.  And the Lolita-esque story doesn't exactly grab me.  But it's his singular, literary approach to telling that story and the edgy, cinematic backing track, which combines session bassist Herbie Flowers's funky, inventive bassline with hard rock guitar and lush orchestral strings, that sell me on the song "Melody" and the album as a whole.
Even if you don't speak a word of French and are utterly turned off by the chain-smoking, dirty old man narrating the song, "Melody" still can be appreciated as a sonically rich, intoxicating piece of early 70s French pop art.

"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.