He is a guitarist and a vocalist of the Boston Celtic punk group Dropkick Murphys.

Instead Tim Brennan was moved up to lead guitar and Jeff DaRosa was brought on to play banjo and mandolin.

[2] Lynch also played in the band Gimmie Danger along with Marc Orrell, Tim Brennan, and Ben Karnavas.

[citation needed] Lynch plays a black early 80s Gibson Les Paul Standard and a black 1981 Les Paul Custom as both his primary and backup guitars for live performances and studio recordings.

He also uses a white 1986 or 87 Gibson ES-175 for, as his tech puts it, "slower, ballad-ey type songs" like "Broken Hymns" and "Cruel", both off of Going Out in Style.