"The Zephyr Song" is a song by the Red Hot Chili Peppers and the second single released from the band's eighth studio album, By the Way, released on August 17, 2002. The song, as a single, was released in two parts. Both editions held two previously unheard-of B-sides, making it, collectively, hold four non-LP tracks. This is the largest number of accumulated unreleased studio recorded B-sides any solitary single the Red Hot Chili Peppers have ever released.
The single peaked at number 6 on the Modern Rock chart, breaking the band's streak of three straight number-one hits.
The working title for the song during the recording sessions was "Coltraine". During the By the Way World Tour, the song was played extensively at most live concerts; however, it has not been played in full since 2004.
The music video on December 1, 2002, was directed by Jonathan Dayton and Valerie Faris. The couple has collaborated with the band on numerous other CDs. It is generally suggestive and reminiscent of a kaleidoscope, by utilizing the same circular and intertwining figures in order to illustrate the psychedelic feel the band was aiming for.
John [Frusciante] and Flea wanted something incredibly, just kind of obscure and psychedelic. Finding true psychedelia in this day and age is really hard to do, because everyone wants to rely on computers and all the stuff that really doesn't know how to find the core of psychedelia. So I had my reservations, but there are some moments in this video where I think it's captured
The song features an audible glitch in the final chorus. The sixth line of "all the world can pass me by” has a wobble in the word “all” at 3:00 minutes. This is present in all releases of the song’s studio version, and has never been corrected.
There is a pressing error on the UK versions of "The Zephyr Song" CD1 and CD2 singles. The CDs and inlays have matching catalogue numbers but the B-sides listed on the inlay are on the opposite disc to the one included with the inlay. Retailers began to switch the CDs in the cases to correct the problem but the catalogue numbers on the CDs were then mismatched with the inlay numbers.