"Can't You Hear Me Knocking?" (The Rolling Stones)

Lyrically, "Can't You Hear Me Knocking?" from 1971's Sticky Fingers is one of Mick Jagger's meh moments.  It's a string of drug references and a semi-coherent story about a guy trying to convince his girlfriend to let him into her apartment after returning from a night on the town.  (Although, knowing Mick and the boys, I'm guessing the lyrics are a druggy, euphemistic plea for extra-marital nookie in the same vein as blues songs like Howlin' Wolf's "Back Door Man.")
Musically, however, this is one of the best Stones tracks ever, capturing the blistering napalm of Keith Richards's riffs as well as the subtler melodic style of co-lead guitarist Mick Taylor.  It's the perfect balance of Stonesian yin and yang.
It's Richards's guitar that you hear as the track opens—a raunchy, staccato burst of flame that ignites the song's slinky groove.  In his autobiography Life (2010), Richards reveals that the song's riff was the simple result of jamming around in the studio and stumbling upon a rhythm that everyone just sort of fell into.
The second half of the song also was the result of jamming, but in this case, Taylor took the lead.  He was enjoying the groove they had going, so he decided to keep on playing after the song was over, not realizing that the tape was still running.  After a couple of bars, everyone else picked up their instruments again and dropped back in, locking into the Latin-tinged rhythm that Taylor and session percussionist Rocky Dijon were working.  
Incidentally, what you hear at the end of the song is the product of a single, improvised take without any edits or overdubbing.
The contrast to Richards's style is pretty stark: Taylor finesses each chord instead of bludgeoning it.  Notes ripple and flow with jazzy nuance as they weave their way around the soulful sax of Bobby Keys.  The burn is slower, but it's still hot.