Pink Floyd's "Shine On You Crazy Diamond" is about their founding member Syd Barrett, who became an acid casualty. Notice the S-Y-D in the title.
The Lady Gaga/Beyoncé collaboration "Telephone" isn't just about turning down an unwanted caller, it's an analog for how Gaga was feeling overwhelmed, like a phone was always ringing in her head.
Roger Daltrey stutters the vocal on "My Generation" by The Who. The idea was to sound like a British kid on speed.
Lil Wayne does an unlikely rap in a remix of the Joe Jonas song "Just In Love." The pair met at the 2008 MTV Video Music Awards.
The Naughty by Nature hit "O.P.P." doesn't have any curse words, but many oversensitive radio stations played a "clean" version with the word "kitten" edited out, surely the first time that word was censured.
Drake's "One Dance" was the first ever song to rack up one billion streams on Spotify.
The Evanescence frontwoman on the songs that have shifted meaning and her foray into kids' music.
Beef with Bon Jovi? An unfortunate Spandex period? See if you can spot the true stories in this Metallica version of Fact or Fiction.
Our chat with Barney Hoskyns, who covers the wild years of Woodstock - the town, not the festival - in his book Small Town Talk.
Tom stopped performing Thompson Twins songs in 1987, in part because of their personal nature: "Hold Me Now" came after an argument with his bandmate/girlfriend Alannah Currie.
A popular contemporary folk singer, Williams still remembers the sticky note that changed her life in college.
With his X-wife Exene, John fronts the band X and writes their songs.