"I have an abiding passion for music and movies," says Randall Poster, the renowned music supervisor of films ranging from Rushmore to The Aviator. His skill is evident in a diverse crop of projects including The Darjeeling Limited, The Nanny Diaries, The Savages and I'm Not There, and forthcoming films Stop Loss by Kimberly Peirce, Revolutionary Road from Sam Mendes, and the feature version of Grey Gardens.

Based in New York City, Poster says he enjoys the challenge of working on both smaller indie films (he got his start with Larry Clark's Kids in 1995 and Wes Anderson's Bottle Rocket in 1996) and larger commercial projects including Old School and Meet The Parents. "The small ones benefit from the work I do on the bigger ones - I can build up a favour bank with publishers and record labels," he says. "And the smaller movies keep me in shape."

No matter what the project, Poster says "my job is to help the director conceive and execute their notion of the music in the movie. It's creating a musical identity for the film."

That can also include pulling a soundtrack together if appropriate, as with his hit soundtracks for films such as Rushmore.

Poster says he can feel the impact of the tough times experienced by the music industry, particularly when it comes to budgeting. "We're in a real transitional period with albums," he explains. "It used to be that if you had a music-driven project, you had record labels clamouring for the rights. That's stopped in many situations, and that means producers can't count on a soundtrack as an additional source to supplement their budget. It's also trickier because record companies are increasingly forced to make money from licensing, so that drives up costs for licensing tracks for films."

Poster's passion is not to just place the latest hit into a film. The Darjeeling Limited's music, for instance, has deeper meaning that even die-hard film fans might miss. The Kinks songs used at pivotal moments in the movie serve as a reference to the band's battling brothers Ray and Dave Davies, echoing the battling Whitman brothers in the film.

Even the more straightforward use of music, like that of Indian film music for Darjeeling, meant extensive research.

"One of the challenges of that was locating it all. There weren't just old soundtracks lying around. It was us scouting on eBay and talking to Satyajit Ray film societies around the world and even working with the Ray family in Calcutta," says Poster.

Another great adventure was working with Todd Haynes (an old classmate from Brown University) on his Bob Dylan experimental biopic I'm Not There. "Todd created just an incredibly intricate cinematic architecture, and the Dylan camp supported us to use all the Dylan music we wanted."