In 1998, I became the classical music manager in a branch of Tower Records in Dublin. It was one of the greatest revelations of my life. As a devotee up to then of composers such as Stravinsky, Webern, Ligeti, Messiean, Takemitsu, Schnittke and Berio, I was surprised to see just how little of this music actually sold. What did sell was the following: the American Minimalists, the English composer Gavin Bryars, the Georgian Kancheli, (the recently deceased) Stockhausen, and some Boulez, but above all, the ‘holy trinity’ of Arvo Pärt, John Tavener and Henryk Górecki. A couple of years later I was working for RTÉ lyric fm, writing and presenting a range of programmes on new music, early music, romantic music and baroque music. And yet, in terms of the listener response, who do you think provoked the most enquiries? Pärt, Górecki, Reich and Ligeti – in that order.

Ligeti was a giant, Reich is inescapable, and it is still intriguing to think that a modern Polish composer could outsell the likes of Madonna with Symphony of Sorrowful Songs. But every Pärt release has sold consistently well and he has gone on to find a much wider audience than all of them.

The Estonian composer Arvo Pärt (b. 1935) is one of those rare creatures in new music: a bestseller. His success, however, has been hard-won, and, within the concentric circles of contemporary music, he has had as many detractors as he has admirers. With Tavener and Górecki he has been patronised with faint praise, damned as a ‘Holy Minimalist’. Some see the popularity of his music as a mere craving for musical simplicity, others for a seeking after the profoundly spiritual, while yet others see it as just a love of beautiful sounds – but whatever ‘it’ is, ‘it’ has helped bring his music to extraordinary prominence.

What the three do have in common is a religious conviction that’s often expressed in an uncomplicated and accessible musical language – especially if you compare it with the complexity of works of relative contemporaries such as Brian Ferneyhough (b. 1943) and American Elliott Carter (b. 1908) – but to suggest that ‘one takes off from where the other finishes’ is nonsense. The success of many of Pärt’s recent pieces demonstrate a continuing appeal, and I have known many people, who, regardless of religious convictions, have been moved by much of Pärt’s music. It seems the people who don’t normally listen to ‘contemporary music’ listen to his. What does that tell us? Are these listeners seeking a kind of consolation that they feel the Church can no longer provide? New music to absolve them of their transgressions?

Each has a distinctive style: Górecki’s approach to the setting of sacred texts in general, as a Roman Catholic, is fundamentally different from Pärt, a devotee of the Russian Orthodox Church. Górecki’s most famous work, his 3rd Symphony – The Symphony of Sorrowful Songs – could not have been written by Pärt or Tavener or anyone else for that matter. The psychological complexity of his musical expression comes in forms that are often ‘simple’ – cumulative repetitions, strong contrasts and so on – but the materials resonate with personal associations: Polish folk-music, religious chant, and the heritage of European art music – whose function may be richly ambiguous.

For an understanding of Pärt’s style, time-travel back to 1976 and the beginnings of his then ‘new’ style, when Estonia was still part of the USSR. The Cantus in Memoriam Benjamin Britten and Tabula Rasa had the Soviet authorities totally bewildered. The regime had only just started to come around to Western compositional techniques – and here was Pärt relinquishing them. Even musicians were baffled by him: the players, who first saw the score of the Tabula Rasa, cried out, ‘Where is the music?’ What is more, his music was now unquestionably religious. He had converted to the Russian Orthodox faith. Whatever about musical modernism, the sacred was still taboo in Soviet Russia.

Pärt has elements of the minimalist approach, but his own peculiar take on it is very different, in part reflecting his own religiosity. Pärt’s whole conception of music is indelibly tied to a sense of art as ritual, art as a spiritual and contemplative revelation. Time is everything in minimalism – no matter what brand you’re dealing with. Everything in minimalism is in the present; the process is here and now, palpable, visceral.

Pärt’s musical language is easy to categorise, but it is not easy to describe. It is minimal in the sense that, in his pieces, small quantities of basically tonal material tend to be developed over seemingly long spans of time. But because it is often monochrome, deliberately anti-dramatic and neutral, it achieves its extraordinary and numinous effect through the simplest of means. It’s often beautiful music but it can often be remote too, and it has a contemplative aura that attracts and/or repels.

In Pärt, the music ushers us into the presence of a recurring process that transcends repetition; and because this is a rite it’s also an act of worship or contemplation – it is T.S. Eliot’s ‘still point of the turning world’. For all that, critics point at Pärt and say that his music has not developed, does not develop and will not endure, that he is effectively stuck in a holy groove.

But Pärt has developed. Sit down with the early masterworks – Fratres, Tabula Rasa, the Cantus in Memoriam Benjamin Britten and then turn to the Stabat Mater, Sarah Was Ninety Years Old, and Passio – a similar approach but on a much bigger canvas. The Kanon Pokajanen, Which was the son of… and Lamentate, however, are new departures. How significant these departures are is too early to tell as yet, but with two major Pärt events this February – the premiere of his first Irish commission in Louth and the RTÉ Living Music Festival in Dublin, we’ll have a chance to hear for ourselves.

CD sales, listener response, critical adulation, critical denigration – how we value any composer can be open to question, and particular only to our own tower from which we survey all around us. Nova on RTÉ lyric fm is the tower I am in at present. We celebrated a two-year birthday recently with a massive giveaway. Any guesses as to which composers the listeners preferred for their free CD?

Baltic Voices in Ireland takes place in Drogheda and Dundalk on 13-14 February. Hosted by The Louth Contemporary Music Society, it features a newly commissioned choral work from Arvo Pärt, performances from the Latvian State Choir, as well as new pieces by Irish composer Deirdre McKay and Latvian composer Georg Pelecis.

The RTÉ Living Music Festival focusing on the music of Pärt, with Scottish composer James MacMillan as Artistic Director, takes place in Dublin on 15-17 February. It features performances from the Hilliard Ensemble, Crash Ensemble, Darragh Morgan (violin), Joanna MacGregor (piano), the choral group Polyphony, the National Chamber Choir, and RTÉ performing groups, as well a commission from David Fennessey. Arvo Pärt will also give a composition seminar led by composer Ivan Moody.

Arvo Pärt will be in attendance at both festivals. Visit www.louthcms.org and www.rte.ie/performinggroups/lmf.html

Bernard Clarke is a presenter with RTÉ lyric fm. His new music programme, Nova, is broadcast on Sundays at 8pm.