Ask the average person in the street what they expect contemporary classical music to sound like and the chances are the answer won't be pretty. Most commonly associated with screeching strings, perplexing pauses, jarring discords and a general head-scratching complexity, many people think of modern art music as something more likely to frighten a child than please the ear.
The halls where this music is performed live, meanwhile, are sometimes feared as intimidating temples of high culture, populated exclusively by pseudy types ready to hiss at anyone who rustles their programme. So far, so forbidding - but are these fears really justified?
Not at all. Certainly, there is plenty of "serious" music from the past 100 years that pushes the boundaries of familiar melodic structure (much of it stunningly beautiful, and not all of it classical - but that's another story). At the same time, contemporary classical music is a wonderfully varied creature, and new composers are often desperately keen to escape the rarefied circles to which their music is too often confined.
A rising generation of classically trained music-makers under 40 are particularly active in breaking down the walls between musical genres, blurring the boundaries between classical and popular styles. Often you're as likely to find their music on Myspace, on fan blogs and in small rock venues as in concert halls, while their musical influences include anything from Gregorian chant to roots folk.
Some of this music is demanding at first listen, and some of it is instantly catchy. While few of this new generation fit perfectly into continuing the classical music canon, they hint at what the future of the western tradition might look like and they are well worth checking out. To get a small idea of the variety that's out there, here are just a few names to look out for.
Nico Muhly
Eclectic, impassioned and surprisingly hip, the 30-year-old American composer Nico Muhly straddles the fence between popular and classical so constantly it's a wonder he hasn't done himself an injury.
With the hugely popular minimalist Philip Glass as his acknowledged mentor, Muhly has so far gained most notice for his collaborations with the Icelandic polymath Björk and the post-rock experimentalists Grizzly Bear, as well as for his haunting soundtrack to the 2008 film The Reader.
At heart, however, Muhly is essentially a composer rooted in the western art tradition, merging the hypnotic loops and rippling textures of minimalists such as Glass and Steve Reich with a love of English renaissance church music by the likes of Thomas Tallis and William Byrd (Muhly started life as a choral scholar), making his music sound completely contemporary and faintly bygone at the same time.
Criticised by that other minimalist great John Adams as showing "a surfeit of prettiness", Muhly's generally tonal music unapologetically aims for (and achieves) beauty even at its most experimental.
His name is likely to become even better known when his upcoming opera Two Boys - based on a true story of internet grooming - premieres with London's English National Opera this winter. In the meantime, check out Muhly's intriguing 2008 album Mothertongue, which meshes minimal electronic sounds with choral and American folk influences to create something strange and rather wonderful.
Daníel Bjarnason
Far-flung Iceland seems an unlikely place to open up new directions for classical music, but the tiny country's music scene has always punched above its weight.
Long isolated from the world's main cultural centres (no orchestra played there before 1926), Icelanders seem to be healthily oblivious to the hierarchies that still dog attitudes to music elsewhere in Europe. Classically trained Björk and epic post-rockers Sigur Ros have always made music with orchestral components, but it is Reykyavik's Bedroom Community record label that is currently going even further, producing music that can't be defined comfortably as either exclusively popular or classical in style.
Founded by the producer/composer Valgeir Sigurdsson, Bedroom Community's music includes the punkish electronic minimalism of the composer Ben Frost, the roots folk of American Sam Amidon, as well as the music of Nico Muhly, mentioned previously.
By far the most rigorously classical of its local stablemates, however, is the 31-year-old composer and conductor Bjarnason. Bleak but tuneful, Bjarnason's recent album Procession, written for chamber orchestra and piano, has a melancholy richness that recalls late romanticism. While lovers of experimental edginess might find it too easy a pastiche of its influences, Bjarnason is not afraid to break through his music's elegant surface with occasional discord, creating a sense of drama and emotional muscle.
Thomas Adès
By far the most celebrated and established composer in this article, the British pianist and composer Thomas Adès has achieved more in his 39 years than many musicians manage in a lifetime.
Performing as a soloist since his early 20s, his brilliant, playful chamber opera Powder Her Face made his name at the age of just 25. Following the true story of a promiscuous 20th-century duchess's decline, the opera dazzled audiences with both its explicit action and its skilful use of motifs from 1930s music (both popular and classical).
His reputation was then cemented by These Premises Are Alarmed and Asyla, both intricate, complex pieces for orchestra whose overlapping rhythms and sometimes jarring chords sit squarely within the modernist tradition (Charles Ives and Alban Berg are acknowledged influences) but still sound entirely contemporary.
There's no mistaking Adès for anything but a composer within the vanguard of the classical tradition - he doesn't reflect the minimalist influences of other composers mentioned here. Nonetheless, his musical omnivorousness - including brief echoes of electronic dance music in Asyla, or referencing 1930s dance bands in Powder Her Face - show someone who is highly aware of a world beyond the concert hall.
This could help explain why his music has proved so popular, performed in major spaces all over the world and seeing him widely tipped as the UK's most promising composer since Benjamin Britten. Indeed, for many classical music watchers Adès is regularly cited as proof that demanding contemporary music can still find a wide and enthusiastic public.
Hauschka
At the opposite end of the scale entirely from Adès is Germany's Hauschka (real name Volker Bertelmann), classically trained pianist and former rapper who would as yet seem quite out of place performing in a concert hall.
Playing almost exclusively in indie rock venues, his music's most obvious kinship is with ambient electronica. Hauschka's first solo albums featured melodic indie pop that adopted experimentalist John Cage's playful use of the prepared piano. An instrument whose sound has been doctored by inserting objects among its strings, the prepared piano has been associated with the experimental avant garde, but in Hauschka's hands it is turned to more tuneful, if still quirky, effect.
More recently, this year's Foreign Landscapes ditches Hauschka's early music's more poppy associations and showcases melancholic, tuneful string music that combines the repeated loops of minimalists such as Steve Reich with the light-handed playfulness of Satie and Poulenc.
Attractive and satisfying, his music's lush, nostalgic sound recalls vaguely the sound of some bygone cabaret (reviving another strand of previously neglected German music), and remains an example of how today's lively cross-fertilisation between popular and classical styles goes in both directions.
