As Scarlett Johansson’s first album, “Anywhere I Lay My Head,” arrives in stores today, the suits over at Rhino Records are hoping they can channel their star’s hipster eminence and box-office drawing power into something more than a novelty item in the class of Scott Baio’s 1982 eponymous debut. It won’t be easy. Whether or not Ms. Johansson’s collection of Tom Waits covers is any good (and the exit polls don’t bode well), the number of mainstream actors who have become mainstream musicians can be counted on one hand. Examples of the opposite are, however, plentiful.

The following is a survey of those who have tried. If we’ve forgotten a few names, it’s only because they were so forgettable.

The Teenyboppers

You can’t blame record companies for ceaselessly turning the innocent faces of children’s television into less-than-innocent pop stars. It’s always worked — from Annette Funicello through David Cassidy, and on to Hilary Duff. In fact, we have only our children to blame. They’ll buy pretty much anything they see on television, they have an insatiable hunger for up-to-the-minute style, and they have the buying power to back it up. Children’s TV veterans Britney Spears, Jennifer Love Hewitt, Lindsay Lohan, Raven-Symoné, and Paris Hilton (we’ll call it television) have seen varied degrees of success in the recording studio, but when you picture the gears of the pop-music machine churning out food pellets for mass consumption, this is what comes to mind (for the most part).

The Former Child Stars

Having acquired a lifetime’s worth of experiences — ranging from the rewarding to the degrading — in only a few years, many maturing child actors figure that if Hollywood is done with them, they’re going to have to find another way to express themselves before someone gets hurt. But while minor child stars have become huge pop figures, and major child stars have been become minor pop figures, none has put it all together.

After her stint on Nickelodeon’s “You Can’t Do That on Television,” Alanis Morissette sounded like a woman who’d been slimed one too many times on her mutliplatinum 1995 debut album, “Jagged Little Pill.” Janet Jackson and Phil Collins each followed small TV roles as children with global pop stardom. And Jenny Lewis (that’s right, Shelley Long’s daughter in 1989’s “Troop Beverly Hills”) has found strong reviews and modest success as a singer-songwriter following her prolific but nondescript early acting career.

Former Soap Stars

In many ways, the target demographic for soap operas comprises the graduates of the Teenyboppers category. Many of the people who watch them, whether they’ve been doing it for 10 years or for 60, would still buy anything with their favorite star’s name on it. But instead of Hilary Duff on the Disney Channel, it’s Rick Springfield on “General Hospital” or Jack Wagner on any of four different soaps. Mr. Springfield was already a popular singer in his native Australia when he suddenly found himself on millions of afternoon TV screens in 1981 and learned that he didn’t know what popularity meant. His presciently titled debut album, “Working Class Dog,” stormed the charts on the back of the lead single, “Jessie’s Girl,” but critical support was not to follow. Apparently, Mr. Wagner was behind the 1984 mega-ballad “All I Need,” which I wasn’t aware of until yesterday.

At 19, Kylie Minogue was an old hand on Australian soap operas when she scored an international hit with her rendition of Little Eva’s 1962 single “The Loco-Motion” in 1988. Ms. Minogue has enjoyed sustained success on the British pop charts through the years, but her pre-music résumé was familiar only to Australians born between 1965 and 1975.

The Meatheads

Matinee idols have a lot of time and money on their hands, and probably know plenty of guys who would agree to play in a band with them if they asked. Bruce Willis, Russell Crowe, Steven Seagal, and others (the Blues Brothers don’t count) have puttered around with rock bands. Keanu Reeves played bass on two-and-a-half albums with Dogstar, and ex-“My So-Called Life” heartthrob Jared Leto has found genuine chart success with his faux-hardcore outfit, 30 Seconds to Mars, making him one of the A-listers in our chart.

Eddie Murphy almost made it stick with his indelible 1985 hit, “Party All the Time” (“My God Is Color Blind” and “Put Your Mouth on Me” didn’t fare as well), but that was because the Superfreak, Rick James, wrote it. By the time Mr. Murphy released “Love’s Alright” in 1993, it had sufficiently not stuck. The following year, “In Living Color” star Jamie Foxx released his debut R&B effort, “Peep This”; 11 years later, Oscar-winner Jamie Foxx (who, it should be noted, studied piano at Juilliard) followed it up with “Unpredictable.”

A common problem with this batch is chronic audience overestimation. Such is not the case with former Starship Enterprise crewmen William Shatner and Leonard Nimoy, who spawned the most loyal and enduring fan base in American history on the original “Star Trek” television series. (Although it was the case, incidentally, with Telly Savalas, who wasn’t able to transform detective Theo Kojak into a lounge singer on two tries with MCA Records.) It is unknown if Mr. Shatner intended for his 1968 recording of poetry and pop covers, “The Transformed Man,” to be the galaxy’s funniest album, even 40 years later, but it’s a serious contender. Mr. Nimoy’s 1969 record, “The Touch of Leonard Nimoy,” was his fourth and last until 1995’s wistfully titled “You Are Not Alone,” which presumably referred to someone other than him being with us.

Female meatheads include Minnie Driver, who has released two widely shrugged-off folk albums, and Juliette Lewis, who, with her bar band, the Licks, plays a passable front woman with a viciousness Mallory Knox couldn’t rival.

The Paper Champions

The aforementioned Mr. Leto leads a small pack of mainstream actors who have managed to prop up careers as mainstream musicians. You probably haven’t heard much from his band’s two albums, but anyone who’s been watching MTV for the last five years (in some cases, five years straight) has. By itself, that wouldn’t earn him an invite into the Paper Champions league — he’s a good fit for the Teenyboppers club — but he wrote all his band’s songs, so we’ll give him a pass.

Kevin Bacon and his brother Michael (an Emmy-winning composer for TV and film) have released five albums as the Bacon Brothers — enough, counting the presence of a professional musician as a member, to elevate them above meathead grade. But they also merit Paper Champion status because they write their own material, and because it seems like they’d still be touring around with their country-stained folk music even if Kevin’s acting career bottomed out. Their rank was imperiled, though, when they made a live album in 2003 featuring a cover of the title song from “Footloose.”

That leaves us with our two lonely winners, a royal couple of dual-action stardom, both of whom have found mainstream success on screens big and small before mounting equally triumphant forays into the world of popular music. You guessed it: Jennifer Lopez and David Hasselhoff.

Mr. Hasselhoff began as a soap star in the mid-’70s, but he hit his stride the following decade as a vigilante with a talking car in the TV series “Knight Rider,” then hit the jackpot as the least appealing body (at least to those who kept tuning in) on the beach serial “Baywatch.” Little known to most of his American audience, though, Mr. Hasselhoff was slowly building a masterful career as a seller of pop records to Europeans. Between 1985 and 2005, he released 15 albums, the second of which, 1989’s “Looking for Freedom,” shot to no.1 in Deutschland on the strength of the title track, which was embraced by thousands of Germans looking for something American and easy to understand.

After a string of films, capped by the 1995 crime thriller “Out of Sight,” made her the world’s highest-paid Latina actress, Ms. Lopez embarked on a similarly lucrative career as a singer, scoring an immediate hit in clubs and clubhouses alike with her debut album, “On the 6.” Subsequent chart-topping albums produced five no.1 hit songs in America and Britain, pushing her close to the 50 million albums mark.