Declan was born the youngest of eleven children and began playing guitar at aged 8, moving on to Mandolin & Banjo. His first taste of playing music in public came when he and his brother Leonard began playing music around the local pubs in Donegal. During this time, Declan toured Scandinavia with Derry band 'Thundering Down' playing music in Sweden, Estonia & Finland, and on board the Viking Line cruise ships 'M/S Mariella' & 'M/S Gabriella' on the Baltic Sea.
Back in Ireland, he also giged with his brother-in-law Martin McCabe's band 'Celtic Swing' playing music around the midlands of Ireland, and on a month long trip to New York City. In 2000, Declan moved to Boston, and began playing with local band 'Inchicore' and guesting with local favourites 'Sundays Well' & 'Ruid Eile' before forming 'Devri' in 2007.
He has played at numerous festivals throughout the States, including Chicago, Pittsburg, Cleveland, New York, Miami, Missisippi & Tampa. With fellow Devri member Larry Flint, he has played music with the legendary Derek Warfield of 'The Wolfe Tones' and has shared the stage with Finbar Furey, Paddy Rielly & Tommy Makem.