Born in Blackburn in 1978, James Weeks read Music at Cambridge before completing a PhD in Composition at Southampton University with Michael Finnissy. His music has been commissioned and performed by leading performers including Alison Balsom, EXAUDI, Darragh Morgan and Mary Dullea, Endymion, Anton Lukoszevieze and Christopher Redgate. He has been featured at UK and European festivals including City of London, Spitalfields, Vale of Glamorgan and Huddersfield Contemporary Music Festivals, Soundwaves Brighton, Cutting Edge (London), Gaudeamus (Amsterdam), Weimarer Frühjahrstage and Mafra (Portugal).

Recent major works include the Harmonies of South London series (for various ensembles, 2008 -), Burnham Air (for oboe d'amore, 2008), Hototogisu (for children's choir, 2007) and Mala punica (for eight solo voices, 2008-9). He is currently writing a substantial work for voices and instruments entitled Parnassus, and a triptych of pieces with electronics for Apartment House.

As a conductor, he is best known for his work with the contemporary specialists EXAUDI, the vocal ensemble he founded with the soprano Juliet Fraser in 2002. With them he maintains a busy international touring schedule, collaborating regularly with the world's leading composers, new music soloists and ensembles, and has released four acclaimed CDs on NMC, of Finnissy, Fox, Lutyens and Skempton. The ensemble specialises in the most complex new and experimental music, often presented alongside repertoire from the Renaissance or early baroque.

He was appointed Musical Director of the New London Chamber Choir in 2007 in succession to James Wood, and is in great demand as a guest conductor, choral animateur and tutor. He is also active as an organ recitalist, pianist and writer on contemporary music, and broadcasts regularly on early and new music for BBC Radio 3.