Mark O’Keeffe held the post of section principal trumpet with the BBC Scottish Symphony Orchestra from December 1996.
In 1992, Mark was chosen as the winner of the RTE Musician of the Future competition. He was subsequently appointed Associate Principal Trumpet of the National Symphony Orchestra of Ireland, a post he held for four years.
He has appeared as soloist with the BBCSSO performing new works by Judith Bingham, Mark Anthony Turnage, Thea Musgrave and Tansy Davies, as well as concertos by Telemann, Haydn, Hummel and Shostakovich.
In addition to his orchestral career, he has played chamber music with Scottish based Red Note Ensemble and London Sinfonietta, and has been guest Principal Trumpet with the World Orchestra for Peace, London Symphony Orchestra, London Philharmonic Orchestra, City of Birmingham Symphony Orchestra, Royal Scottish National Orchestra, Royal Liverpool Philharmonic Orchestra, Royal Opera House Orchestra, BBC Symphony Orchestra, Halle Orchestra and Symphony Orchestra of India.
Mark was awarded a Creative Scotland bursary in 2004 for a collaborative project with Theatre Cryptic.
He has lectured in trumpet studies at the RCS Glasgow, the RNCM Manchester, NESMS in Aberdeen, and was awarded a distinguished alumni of MTU Cork School of Music in 2018 where he lectures full-time in trumpet studies since September 2025.