Becky Bentham and Karen Elliott of London-based Hot House Music like to think of themselves as a "one-stop shop" for film music.

They are a boutique agency for composers, provide music supervision and score co-ordination, and can even create hypothetical budgets at the financing stage. They are presently working on How To Lose Friends And Alienate People, The Golden Compass and Mamma Mia!

As Elliott explains, they can also go above and beyond the usual scoring or licensing. For Gurinder Chadha's teenage story Angus, Thongs And Full-Frontal Snogging for Paramount, Elliott even created a band, The Stiff Dylans, which may go on to secure a separate label contract outside of appearing in the film.

A music supervisor's involvement can depend on the film's director. "Some directors have very clear visions but generally those visions are outside their budget range, so it will then fall into my lap to make suggestions for similar songs," says Elliott.

"Other directors have no idea of what they want and leave it up to me to come up with suggestions."

For a film such as Olivier Dahan's La Vie En Rose and the new adaptation of Abba musical Mamma Mia!, Bentham was brought in "from day one, and involved every step of the way", including pre-shoot recordings with the cast, set visits to supervise lip-syncing, and attending post-production.

For projects that do not need full music supervision out of the UK (including most studio films), the Hot House team can still come on to co-ordinate scores, as they did with The Lord Of The Rings trilogy.

"That had various challenges. There was an incredibly large team of people to be co-ordinated," Elliott explains. "And we didn't lock the picture until a very late date so we were trying to record 24 hours a day, seven days a week while still keeping on budget."

The UK is a popular place to record scores for many studio films due to the quality of the territory's session musicians and because of more lenient rights. In the US, after a soundtrack sells 50,000 units, score musicians have to be paid again, whereas in the UK they are paid once for all sales.

The increased flexibility and speed of the digital age means the days of writing music to a locked picture are over. Elliott advises: "Get a music supervisor involved earlier, and be realistic with budgets - don't think you can clear Bob Dylan for $10,000."