Tiarnan learned the uilleann pipes with the Armagh Pipers Club under the tutelage of Brian Vallely and Mark Donnelly. He first started playing the tin whistle and drums at age 3 (!) progressing onto the pipes at 9.

His achievements to date have included winning All Ireland titles as well as the prestigious Oireachtas Piping competition in 1997 in the Centenary year of the event. He performed as a soloist in the Edward Maguire commissioned orchestral work "L'Epopée Celtique" at Festival Interceltique in Lorient also in 1997.

Tiarnan has recorded and performed with various artists as diverse as Hazel Ó Connor, Vards, Danish rock singers and Gaelic singers like Aoife Ní Fhearraigh. His playing has featured on two movies as well as numerous advertisements and he has recorded and toured with Maire Brennan (Clannad). He played with the New Scottish and Irish orchestras alongside work in the Abbey Theatre, Dublin and with his band Dorsa he recorded a widely acclaimed CD and toured extensively.

Tiarnán is one of the tutors in Armagh Pipers Club and has a great reputation as an inspiring teacher, counting a number of star performers among his pupils. He is also one of the driving forces behind Club Muinneachain, organising successful gigs in his native Monaghan. He has been strongly influenced by the playing of pipers Séamus Ennis and Johnny Doran and the Donegal fiddler Johnny Doherty.