Although the first third of "Can't You Hear Me Knocking" is an elemental blues-rocker built around some of the Rolling Stones' most insistently memorable basic guitar riffs, it changes to a Latin-flavored instrumental highlighting fluid Mick Taylor guitar and jazzy saxophone by Bobby Keys. The instrumental section was an unplanned jam that the band decided to keep as part of the song after listening to the playback. "That song had such a fantastic groove going, they just left the tape running for my solo at the end," enthused Mick Taylor in MOJO.
After visiting islands made famous by Homer's Odyssey, artist Martin Sharp (who would go on to do the cover art for Cream's Disraeli Gears) wrote this poetic tune to the melody of "Suzanne," specifically, Judy Collins' cover of Leonard Cohen's song. Through a mutual acquaintance, Sharp got the lyrics to Eric Clapton, who worked them into a guitar riff inspired by the Lovin' Spoonful's "Summer in the City." The song marked Clapton's first use of the wah-wah guitar effect. "I always liked that song," said Jack Bruce, who sang it. "I think it was the wah-wah that did it for me. I'm a sucker for wah-wah."