Given the fleeting nature of fame, it would stand to reason that becoming a celebrity would itself be reward enough. But for many high-profile public figures, that simply isn't the case.
Every year, the list of artists, actors, authors and other celebrities dabbling in popular music grows. Keanu Reeves, of "The Matrix" and "Speed" fame, has long endured ribbing for his gigs with rock band Dogstar; "Face the Nation" host Bob Schieffer occasionally performs with country outfit Honky Tonk Confidential; and even mercurial actor Joaquin Phoenix is getting into the act, recently announcing that he's swearing off Hollywood and embarking on a career as a rapper. But it's too early to tell if Phoenix is merely engaged in an elaborate prank. (He's already got the drama down. He attacked a fan at his Miami concert a few weeks ago, but even that episode - caught on video by his brother-in-law Casey Affleck - could be a joke.)
Here's a look at some musical celebs - the good, the middling and the awful.
Kevin Bacon . Bacon and his older brother, Michael, have been performing as folk-tinged, country-rock duo the Bacon Brothers since 1995, releasing five studio albums. Their straightforward sound is clean and pleasing, with a minimum of look-at-me, rock-star posturing.
Zooey Deschanel . The public first got a glimpse of Deschanel's talent in 2003's "Elf," in which she crooned a few bars of "Baby It's Cold Outside." Teamed with acclaimed indie rock singer-songwriter M. Ward to create the band She & Him, Deschanel wowed the critics on the pair's 2008 debut album, "Volume One." Lilting vocals and shuffling, folk-flecked instrumentation didn't just win fans - she's engaged to Death Cab for Cutie frontman Ben Gibbard.
Minnie Driver . The star of FX's "The Riches" and such films as "Good Will Hunting" and "Grosse Pointe Blank" was involved in music before her acting career took off. She returned to the world of roadies and recording studios with 2004's "Everything I've Got in My Pocket," a critically acclaimed disc.
Daniel Handler . Best known by his pen name - Lemony Snicket - author Handler also has some indie-rock cred. While not officially a member of the Magnetic Fields (he's contributed to a few of the group's albums), Handler has collaborated with Fields mastermind Stephin Merritt on several projects, including Merritt's "goth-bubblegum" band the Gothic Archies.
Billy Bob Thornton . His work with the Boxmasters is pretty spot-on. Thornton describes the Boxmasters' sound as "electric hillbilly music," which undersells the funny country colors evident on songs like "The Poor House" and "She's Lookin' Better by the Minute."
Band From TV . Led by "Heroes'" Greg Grunberg, this motley collective of TV actors includes Hugh Laurie, James Denton, Teri Hatcher, Adrian Pasdar and Bob Guiney, to name a few. The group's raison d'etre is benefiting charities, but their sound skews a bit too karaoke for comfort - it's not for nothing their debut CD is called "Hoggin' All the Covers."
Kevin Costner . If you were surprised by the appearance of Modern West, the country-rock group fronted by Oscar winner Costner, you haven't been paying attention. Before he felt the urge to cut a record and tour the country, Costner had dabbled in the music biz with the Kevin Costner Band and recorded a duet with Amy Grant, "You Didn't Have to Be So Nice," for his 1997 film "The Postman."
Russell Crowe . Most folks probably wouldn't immediately peg the Aussie actor as the sensitive artistic sort, but that's exactly the side of himself he revealed in 30 Odd Foot of Grunts (renamed The Ordinary Fear of God), which has released four albums.
Scarlett Johansson . More at home in the tabloids and on the big screen, Johansson rankled a lot of hipster bloggers in 2008 by recording an album comprising largely Tom Waits covers titled "Anywhere I Lay My Head."
Jared Leto . In 1998, he returned to his first love with the formation of 30 Seconds to Mars, an emo-ish alt-rock band that's proven quite popular at home and abroad. The band is embroiled in a lawsuit with Virgin Records, but that's OK - it's just delaying more screamed, furiously strummed pap.
Corey Feldman . His acting ability is just as questionable, so it should come as little surprise that his musical chops are suspect, too. With help from Corey Feldman's Truth Movement, the actor has made the world safe again for subpar rock.
Juliette Lewis . Formed in 2003, Juliette and the New Romantiques (formerly the Licks) are a showcase for actress Lewis' punky proclivities, complete with lots of atonal sing-speaking, painfully amateurish lyrics and rote punk-inspired riffs.
Steven Seagal . What sounds like an amusing "Saturday Night Live" skit is, in fact, reality. The star of such classics as "Under Siege" and "Hard to Kill" has been quietly building a music career as - get this - a blues guitarist.
Jada Pinkett Smith . Her husband, Will Smith, has a popular, profitable rap career to go with his acting, but Pinkett Smith's forays into the music world are much less appealing. As the front woman for the headbanging Wicked Wisdom, a metal band formed in 2002, Pinkett Smith has opened for Britney Spears and appeared at Ozzfest.