Remember when people used to talk about 20th-century music? It was a euphemism. It wasn’t really used to refer to Ravel, Rachmaninov or Sibelius. Stravinsky counted, Shostakovich was probably borderline, but Schoenberg, Berg and Webern, and their successors in the avant-garde of the 1950s and 1960s definitely qualified.

I’ve often wondered where this practice came from, of using “20th-century” in relation to music the way “Dublin 4” is used in relation to the residents of that particular postal district. Living in Dublin 4 certainly doesn’t give you an automatic qualification, and you can be “Dublin 4” without actually living there.

My best guess is that it all started with the Internationale Kammermusikaufführungen Salzburg 1922, a festival of modern chamber music presented as part of the Salzburg Festival. It was regarded as such a success by the composers involved that it was established as a separate entity. It spawned an organisation that survives to this day, the International Society for Contemporary Music (ISCM), and the festival, which quickly expanded beyond chamber music, does too. It’s now known as the World Music Days, and takes place every year in a different country.

The bifurcation into what’s known as “new music” seems to have been immediate, as the ISCM’s German title used the German word for “new” rather than the word for “contemporary”. But the ISCM was riven by arguments. As The New Grove Dictionary of Music and Musicians explains: “There was conflict between those countries that felt that it should promote avant-garde music (principally Germany before 1933 and Austria and Czechoslovakia before 1938) and those that considered any contemporary music to be worthy of the society’s interest (principally France, Great Britain and the US).”

So, if “contemporary” was compromised as a description of what was really new, then perhaps “20th-century” could be used to describe an aesthetic position that left the flavours and practices of the 19th-century behind. And when the obviously inaccurate “20th-century” didn’t work, there was always the notion of the avant-garde, very popular in the 1950s and 1960s, to turn to.

Dublin had its own Festival of 20th-Century Music from 1969 to 1986 and there have been short-lived successors, such as Accents, which brought György Kurtág, Music Now, Mostly Modern, and, from 2002 to 2008, the RTÉ Living Music Festival, fondly remembered for focuses on Steve Reich and Arvo Pärt (who came to Dublin) and John Adams (who was prevented from coming by birthday celebrations).

The latest such festival, New Music Dublin, a five-year initiative by the Arts Council, with the National Concert Hall, RTÉ and the Contemporary Music Centre as partners, ran from Friday to Sunday. It was an all-embracing venture, reaching out into jazz and ambient music, and allowing viola-player Garth Knox’s trio Saltarello to venture as far back as Hildegard von Bingen and include traditional arrangements in a programme that made complete sense. The highlight was percussionist Sylvain Lemêtre’s performance of Georges Aperghis’s Corps à corps, a mesmerising tour-de-force of combined talking and drumming.

Swedish trombonist, composer and conductor Christian Lindberg’s new Kundraan and the Arctic Light, premiered by the RTÉ NSO on Friday, was doubly amazing. Lindberg featured in a quadruple role, as composer, conductor, trombonist and narrator, and kept everything superbly together. But the work itself was a musical washout: naive, trite, an empty showcase.

The Fidelio Trio’s programme offered a work by Glasgow-based Irish composer David Fennessy that was at once obvious and bizarre. He wrote his trio Music for the pauses in a conversation between John Cage and Morton Feldman in 2010, and the title says it all. Cage and Feldman recorded conversations for radio in the 1960s, conversations that are extraordinarily unhurried, with the sorts of pauses that you would expect radio producers to edit out as a matter of course.

Fennessy chose the conversation from July 9th, 1966, which opens: “John, wouldn’t you say that what we’re dependent on, we call reality, and what we don’t like, we consider an intrusion in our life? Consequently, I feel that what’s happening is that we’re continually being intruded upon./But that would make us very unhappy./Or we surrender to it, and call it culture./Call it culture?/Or whatever./Give me an example.” Hard as you may try, you probably can’t imagine how many pauses that opening gave Fennessy to fill, or how well he’s filled them in a way that both of the other composers might appreciate.

Neglected music

One of the obvious functions for the New Music Dublin Festival is to give Irish audiences a chance to catch up with works that are not new, but which have been neglected by the musical establishment here. On Saturday, the RTÉCO under Reinbert de Leeuw brought the angry insistence of Dutch composer Louis Andriessen’s seminal De Staat of 1976, a pungent, punchy, heavily amplified setting of Plato that changed the face of minimalism.

It was offered in a chalk-and-cheese programme that went on to offer the Irish premiere of Arvo Pärt’s Fourth Symphony (Los Angeles), which was premiered by the Los Angeles Philharmonic in January 2009. The connection between the two works is non musical. De Staat was intended as “a contribution to the debate about the relation of music to politics”. The symphony is provocatively dedicated to the imprisoned Russian oligarch Mikhail Khodorkovsky, and Pärt has said that he wants to reach out also to “all those imprisoned without rights in Russia”.

Saturday’s performance of the De Staat had a rough energy. But that of the altogether calmer symphony was flat, the RTÉCO simply too small on the night to provide the warmth or occasional massiveness of tone that the music needs.

Massiveness and impact are characteristics that the Crash Ensemble rarely lack. And in the smorgasbord of Heiner Goebbels’s Red Run the sequenced solos all worked a treat. Goebbels works rather like a master chef, who always makes sure there’s an unlikely flavour in the mix, an intriguing, often marginal presence that manages to transform the experience of what’s in the foreground.

One of the treats of the festival was the delivery of so much that was free. These were not just formal concerts, but also boutique performances in tiny spaces, with opportunities to engage directly with performers (lots of families took up the option), and “creative labs”, where the public could engage with artists at work.

There were shortcomings, too, most of them so obvious that the organisers will hardly fail to fix them next time round. And there was one major discovery that should have ramifications well beyond the festival. Crash’s concert was given in the former Engineering Reading Room, a high-ceilinged space at the back of the Earlsfort Terrace building, which even in its rather decrepit condition has huge potential as a small concert space.