Its nature as a festival that is fundamentally about standard orchestral repertoire means that the Proms continues to exhibit a slippery relationship with new music. Challenging works still appear to be sidelined while showy, more conservative pieces end up in prime slots with big audiences. Whether or not this is the right way round remains open to debate and, indeed, the bustle of social media has provided an interesting platform this year for discussion around the issue.

As suggested by its title, Tansy Davies's new opera Between Worlds is more fantasy than a representational depiction of historic events. Co-commissioned by ENO and the Barbican, where it was premiered on 11 April 2015 with a superb cast conducted by Gerry Cornelius (I attended on 21 April), it raises a central aesthetic and political question about the extent to which public figures of our time can be drawn and re-drawn in art. Recent docu-operas, such as Nixon in China, the more recent Anna Nicole and, of course, the highly controversial The Death of Klinghoffer suggest the issue is a live one.

The Linbury Studio Theatre at the Royal Opera House in London has hosted an impressive range of intimate experimental music theatre works over the last few years. The 2014/15 season, for example, has featured prominent premieres of new works by Harrison Birtwistle and David Harsent, and a ballet staging of John Adams' Shaker Loops, amongst a range of other interesting concerts and shows. The late-April premiere run of Matthew Rogers's The Virtues of Things and an early-May staging by Netia Jones of Georg Friedrich Haas's song-cycle on fragments of Sappho, Atthis, showed how well the Royal Opera uses the smaller space and shorter runs common to the Linbury to programme in quick succession such distinctive pieces from across the spectrum of contemporary music. Atthis, which I attended on 24 April 2015, was perhaps the more intriguing of these two shows, since in conception and execution it was so bold; though Virtues has its own qualities, to which I'll get in a moment.

Three new piano works premiered at the 2014 Proms showed an intriguing variety of styles and idioms in twenty-first-century music with varying levels of success. Paradoxically the more inventive piano techniques emerged in the more vividly characterised and communicative works by Judith Weir and Zhou Long, while Bernard Rands' neo-modernist concerto lacked a clear identity.

How many flutes are there in Simon Holt's flute concerto Morpheus Wakes? Nominally one, here the amazing Emanuel Pahud, but more usefully two or more. Scored for alto as well as standard flute, Holt exploits the timbral possibilities of both while ensuring that the orchestra's own flautist (doubling bass flute) and alto flautist (doubling piccolo) continue the idea of ‘two-in-one’ so central to his other recent concerto Centauromachy for clarinet, flugelhorn and orchestra written in 2010 and given its London premiere at the 2011 Proms.

Broad textures, clear but unforced musical statements, a focus on tone and sound colour – at the 2015 Estonian Music Days festival all these characteristics of music from the Baltic states were much in evidence, yet its many young composers are all taking these ideas in different directions. The result, judging from the opening weekend of the festival, is a collection of works emerging clearly from a singular musical tradition, but energised by continually expanding diversity and invention. The vibrant new music scene here in Estonia belies the country's diminutive size.

Amidst the wide range of events staged as part of Glasgow's 2014 Cultural Programme in celebration of the Commonwealth Games, the New Music Biennial Showcase occupied the closing weekend of the Games. Hosted at the Glasgow Royal Concert Hall on 1 and 2 August, it made use of three separate performances spaces: the main hall, the newly redeveloped Strathclyde Suite and the more intimate brand new City of Music Studio. As at its London partner event, which took place between 4 and 6 July at the Southbank Centre, audiences were provided with an opportunity to hear 20 new commissions from a diverse selection of composers from across Britain, each of which had already been performed across the country in a variety of locations, ranging from skate parks to concert halls.

Philip Glass is so prolific a composer that it is tempting to wonder whether he has become entrapped by his trademark restlessly repeating patterns. At the age of 77, there is no diminution of his prodigious energy; The Trial brings his tally of operas to some 30 since he first shot to fame – or notoriety – with Einstein on the Beach in 1976. Glass is, in effect, an iconoclast-turned-icon, and he is now by far the most performed contemporary composer of opera on the planet.

Following its premiere at the Whitney Biennial in Spring 2014 (for which, with very limited seating, tickets were effectively unavailable), Robert Ashley's last opera, Crash (2014), had a run at Roulette in Brooklyn this April. The composer passed away just before its premiere, leaving us with an elegant final word in a daunting body of work but also with the challenge of situating this opera within Ashley's artistic legacy.

The torch of artistic direction has passed from Matthias Osterwold to Berno Odo Polzer. Under the former, MaerzMusik was unique among the large European international festivals for its focus on interdisciplinary concerts, sound installations, crossover projects and use of digital media. Concerts often took place in alternative venues ranging from Berlin's most (in)famous nightclub, Berghain, to the Hamburger Bahnhof, a train station transformed into a museum of modern art. The home of the festival, Haus der Berliner Festspiele, was almost exclusively employed for sound installations and music theatre performances. One always had to be sure to buy tickets in advance for fear of facing a sold-out concert; the capacity of the alternative venues was often limited.

2014, Sir Harrison Birtwistle's 80th birthday year, witnessed a plethora of events celebrating his music, from the Barbican's ‘Birtwistle at 80’ series to the ‘In Broken Images’ concerts at the Southbank Centre. Included in the latter was the UK premiere of his new concerto for piano and orchestra, Responses: Sweet disorder and the carefully careless, performed on 6 December 2014 by Pierre-Laurent Aimard and the London Philharmonic Orchestra under the direction of Vladimir Jurowski. Birtwistle describes the concerto as addressing the problem of ‘the relationship between the piano and the orchestra’, with the subtitle (taken from essays by architect Robert Maxwell) expressing the ‘essence’ of his composition.

Based in a small market town just inside the Welsh border, the Presteigne Festival annually punches well above its weight in contemporary music terms. The conductor George Vass has been Artistic Director at Presteigne for 22 of its 32 years, and his tireless advocacy of living and lesser-known composers has garnered not only increasing international respect, but a loyal and substantial audience, including many locals for whom encountering ‘new music’ has clearly become something to relish rather than suffer.