Called “thrilling” by the Guardian, and “arrestingly beautiful” by the New Yorker, Donnacha Dennehy’s music has featured in festivals and venues such as the Berliner Festspiele, Edinburgh International Festival; Carnegie Hall (which has co-commissioned three works); Barbican, London; Muziekgebouw, Amsterdam; Wigmore Hall, London; Royal Opera House, London; BAM, New York; St. Ann’s Warehouse; Tanglewood Festival; Holland Festival; Kennedy Center; Huddersfield Contemporary Music Festival; Dublin Theatre Festival; ISCM World Music Days; Bang On A Can; Ultima Festival, Oslo; Musica Viva, Lisbon; Saarbrucken Festival; and the Schleswig-Holstein Festival.  

His music has been premiered and commissioned by groups and soloists including Alarm Will Sound, Augustin Hadelich, Bang On A Can, Contact, Crash Ensemble, Dawn Upshaw, Doric String Quartet, Fidelio Trio, Joanna MacGregor, Kronos Quartet, Icebreaker, LA Philharmonic, Nadia Sirota, Konzerthaus Orchester Berlin, National Symphony Orchestra of Ireland, Oregon Symphony, Orkest de Volharding, Percussion Group of the Hague, philharmonie zuidnederland, San Francisco Contemporary Music Players, So Percussion, St. Paul Chamber Orchestra, Third Coast Percussion, Ulster Orchestra (BBC), and United Instruments of Lucilin (Luxembourg). Collaborations include pieces with the writers Colm Tóibín (The Dark Places), the director Tom Creed (The Hunger, stage version) and Enda Walsh (a trilogy of operas). 

Returning to Ireland after studies abroad, principally at the University of Illinois, Dennehy founded Crash Ensemble, Ireland’s now-renowned new music group, in 1997. Alongside the singers Dawn Upshaw and Iarla O’Lionáird, Crash Ensemble features on the debut 2011 Nonesuch release of Dennehy’s music, entitled Grá agus Bás. Other releases include a second portrait disc by Nonesuch (The Hunger, 2019), a number by NMC Records in London, Bedroom Community in Reykjavik and New Amsterdam and Cantaloupe in New York. Nonesuch are releasing a third portrait CD, Land of Winter, in November 2024.

In recent years, Dennehy has concentrated especially on large-scale instrumental and musico-dramatic works. He has now completed a trilogy of operas with the writer/director Enda Walsh: The Last Hotel (2015), The Second Violinist (2017) and The First Child (2021); and a docu-cantata The Hunger (2012-16, concert version 2019), originally co-produced by Alarm Will Sound and Opera Theatre St. Louis. 

Large-scale instrumental works include Land of Winter (2022), premiered by Alarm Will Sound at Beethovenfest in Germany, Limina (2023), a piano concerto for Eliza Mc Carthy and ensemble, premiered at New Music Dublin in the same year, Overcasting (2019), commissioned by the LA Philharmonic, and Tessellatum (2015-16), an epic piece for viola (Nadia Sirota) and microtonally adjusted viols, originally multitracked by Liam Byrne in the Bedroom Community recording, but now arranged for various ensembles, including a string orchestra of modern instruments in a new version of 2020 that will receive its official premiere with Sirota and the LA Phil in the fall of 2024. Recent orchestral pieces include Brink (2020) for Indianapolis Symphony, Memoria (2021) for the National Symphony Orchestra of Ireland (US premiere by the Dallas Symphony in May, 2022) and Violin Concerto (2021), co-commissioned by the Oregon Symphony, Aspen Music Festival and philharmonie zuidnederland for Augustin Hadelich. The Konzerthaus Orchester gave the German premiere, conducted by Joanna Mallwitz, at MusikFest Berlin in the Autumn of 2023.

Dennehy’s single-movement orchestral piece Crane was ‘recommended’ by the International Rostrum of Composers (2010). In 2017, he won the FEDORA-Generali Prize for Opera (Salzburg/Paris), and in 2021 he was awarded a Guggenheim Fellowship. In 2024 he won a Koussevitsky commission. He now lives in America and is a professor of music at Princeton University. His music is published by G. Schirmer in New York.