It's disturbing news that 23-year-old actor Scarlett Johansson will release an 11-track album in May. Anywhere I Lay My Head features ten Tom Waits covers and one original song. The internet buzz is that it "might actually be good".

This album is thus hyped because it is produced by the highly rated David Sitek of New York indie rock band TV on the Radio, and features members of the equally cool Yeah Yeah Yeahs. This choice of collaborators is taken to mean that, supposedly, Johansson is even hipper than she looks (and let's face it, looking the way she does, she does not really need to be very hip at all).

Why on earth does a Bafta award-winning actor need to waste her time messing around with cover albums - however good? Was her karaoke turn in Lost in Translation - where she serenaded Bill Murray with the Pretenders' "Brass in Pocket" (a sweet and poignant movie moment) not enough?

It seems strange that a successful actor like Johansson is not already achieving her life's ambitions. Something is missing. She wants more. She wants to sing and was even seriously canvassed as a potential Maria in Andrew Lloyd Webber's The Sound of Music before the casting turned into a reality TV show. In 2006 she recorded a version of "Summertime" for a charity album. In April 2007 she performed on stage with the Jesus and Mary Chain in California, proving she could sing live. But what does she have to prove?

Johansson is by no means a mediocre actress. She has starred in a few so-so commercial films (The Nanny Diaries, The Horse Whisperer) but when she has chosen roles wisely, she has performed brilliantly (Girl With a Pearl Earring, Lost in Translation). Woody Allen regards her as a muse and has cast her in two films, comparing her to Marilyn Monroe.

But at 23 Johansson is far too young to write off acting.

Unless there is a Barbra Streisand thing going on (which one hopes there isn't - there's only room in this world for one Barbra), this must be about the lure of rock stardom. It is obviously not sufficiently thrilling to just be a "hot" movie star.

Johansson is not alone in this pursuit of hip. Last year Juliette Lewis - another actress who has the potential to be great - released a punk album with her band Juliette and the Licks. They are painful to listen to and even more painful to watch. In the US, Lindsay Lohan, Hilary Duff and the Simpson sisters all market singing as well as acting as part of their allure. But they are not future Oscar hopefuls.

Johansson might learn a lesson from actresses whose voices were good enough to pursue singing, but who have kept well away from the recording studio.

Nicole Kidman has an excellent voice - artfully revealed in Moulin Rouge - as does the stage-school-trained star of Chicago, Catherine Zeta-Jones. These two Hollywood veterans know that if you want recognition as an actor you keep your singing voice quiet - unless the role demands it.