It used to be that rock and classical couldn’t be in the same room together – literally in some record shops – but Jonny Greenwood, Nico Muhly and Dustin O’Halloran have broken down the walls

WHEN COMPOSER Nico Muhly released his first solo work, he chose not to release it via a classical music label. Instead, Speaks Volumes, from the Juilliard student and Philip Glass protégé, found a home on Bedroom Community. The Icelandic collective counts among its musical founders Valgeir Sigurðsson, who has produced albums for Feist and Björk.

Earlier this week, speaking ahead of his Young Americans show with Crash Ensemble in Dublin tonight, Muhly acknowledged the distinction between the many facets of his music – but in an unexpected way. “I don’t tend to think I’m making classical or non- classical music; I like to say that I’m either in collaborative mode or non-collaborative mode, which is a slightly sneaky way of dividing up the year. A collaboration can be with anybody from a choreographer to a theatre director or a rock band. But when I’m alone, I’m alone.”

Muhly’s work has encompassed classical commissions and operas, but he has also overseen arrangements for acts such as Grizzly Bear, Antony and the Johnsons, and Bonnie “Prince” Billy. In terms of his influences, New York-based Muhly is happy to cite 16th-century religious composer William Byrd in the same breath as Prince.

Rather than locking into a push-pull conflict, the eclectic expanses of his musical interests coalesce. “I haven’t yet found that there’s such a jarring imbalance in what I’m doing,” he says, “but if sometimes I feel like I’m doing too much of one thing, it’s less about the type of music, more an indicator that I’m in the tech week for that work, where it’s all very intense.”

Earlier this month, former Coral guitarist Bill Ryder-Jones released his debut solo album, If, on Domino Records imprint Double Six. Fans of the jangly riffs he contributed to his former band will be surprised not just by the sound and scope of the project, but by its concept. Ryder-Jones took Italo Calvino's 1979 novel If on a Winter's Night a Travelerand added layers of orchestral instrumentation. Liverpool's Philharmonic orchestra was commissioned and, overall, it's a project whose ambition is equal to its success.

What's most interesting is that Ryder-Jones's previous forays into composition were linked to film. All three were for short films – two of his own and one for a friend – and one feels that Ifwas made not just as an experiment but as a calling card. Rather than wander hopefully down Sunset Boulevard with a sandwich board, Ryder-Jones has shown Hollywood that he can do layered minimalism and orchestral sweep with the best of them.

Crossing over into classical is an obvious move for musicians who feel constrained by traditional instruments or the rubrics of a conventional band. Radiohead’s Jonny Greenwood has increasingly gravitated towards the sonics of composition, while maintaining his role in the band.

In 2004, a year after Hail to the Thiefwas released, Greenwood was appointed composer-in-association with the BBC Concert Orchestra. A piece he made there, Popcorn Superhet Receiver, formed the basis for his score for Paul Thomas Anderson's There Will Be Blood.This year he agreed to score Lynne Ramsay's chilling adaptation of We Need To Talk About Kevinafter reading the script (he initially turned it down, citing time constraints).

Greenwood’s Radiohead profile undoubtedly means he has brought fans of the band into the classical arena, where they mightn’t otherwise have ventured.

This works both ways, with reciprocal moves for classical acts that find new – and younger – audiences with wider musical palettes. Take American pianist and classical composer Dustin O'Halloran, whose accomplished opuses and preludes have graced various ads and TV shows. That exposure certainly contributed to O'Halloran's Lumierealbum being released by the very progressive Fat Cat label (home to acts as diverse as Animal Collective, Hauschka and Vashti Bunyan). Iceland's mercurial Jóhann Jóhannsson – whose work includes albums, soundtracks and music for theatre – found a similar alternative base in UK label 4AD (home to St Vincent, The National and formerly The Pixies).

For Nico Muhly, when people discover music outside of their comfort zone, it’s always a good thing. “I’m happy if somebody listens to me because they read about me, but even happier if it comes via another musician. I think the demise of the record shop itself has helped with this – once upon a time, buying classical music was like buying pornography, where you had to go into a little special room off to the side and men with sticky fingers and questionable body hair would carry on about the moral failings of one tempo versus another tempo in a recording. Now there is a more lateral listening, where people can come to my music via, say, Grizzly Bear, and from there move on to somebody like Sam Amidon, or to Timothy Andres or Judd Greenstein.”

Classical composition also provides a natural home for the tricky beast that is the concept album. One of the reasons Kate Bush's new work , 50 Words for Snow,is so effective is because the lengthy song-cycle structure works so well in a classical context. That she chose to pare things back to piano and strings also indicates the classical leanings of the album.

Themes that can be difficult to represent aurally are often best suited to the opera form. When Nico Muhly tackled polygamy in Dark Sistersand a murderous friendship in Two Boys, he presented them as operas. "With dark, intense, layered themes, opera is the best way to go, and maybe less specifically but more accurately, theatre, because theatre can get at things in a way that music alone can't always."

Two films this year, Blue Valentineand Jack Goes Boating, credited Muhly, who had reworked Grizzly Bear's Veckatimestalbum as the bulk of the score for both. "It's a complicated reworking of existing material, but sometimes needle-dropping records into a movie is indicative of either a lack of imagination or of a huge imagination."

For musicians such as Muhly, Greenwood and Jóhannsson, music is as uncompromising as it is panoramic, and the Venn Diagram of crossover is where you’ll find them.

Nico Muhly plays as part of Crash Ensemble’s Young Americans programme tonight at Dublin’s Liberty Hall. crashensemble.com