Gaelic Doom Metal or Ceol Breatha Gaelach has its roots very firmly based in the traditions of Old Gaelic Irish Music and Doom / Death Metal. The pace of the music tends to be slow to mid-pace, primarily played in natural minor scales and relying on a variety of time signature changes within each song to convey the mood being created by its lyrics.

A delicate mix of acoustic folk and electric instruments are used to add to this mood while the vocals rely heavily on the Sean Nós style of Irish singing to unite the music and lyrics together. Lyrical content is varied but tends to have the same subjects employed by the Gaelic poets of the 15th, 16th and 17th centuries and so include the themes of love, dispossession, hate and history, dreams, elegies and laments, regrets and commemoration of the old ways slowly dying.

Instrument that have been used to date in the playing of Gaelic Doom Metal include whistle, low whistle, bodhrán, cláirseach, uilleann pipes, lyre, mandolin, horn, piano as well as the standard keyboards, electric guitar, electric bass and drums (used in most forms of modern metal music)