The brothers formed Brigyn in 2004 after the break-up of their previous group Epitaff. After signing to the Gwynedd label Gwynfryn Cymunedol, their eponymous debut album was released in late 2004. A Welsh-language release, the album received considerable airplay on Radio Cymru; one of the tracks, 'Sonar' was selected by BBC Radio 1 DJ Huw Stephens for inclusion on the Dan Y Cownter showcase CD released by the Welsh Music Foundation in 2005. Later that year, a second album, Brigyn2, was released on Gwynfryn Cymunedol.
In 2006, Brigyn toured Wales, playing the Sesiwn Fawr festival in Dolgellau in July and the Green Man Festival later in the summer. A tour of Ireland soon followed. Also in 2006, the remix CD Ailgylchu was released, containing remixes by Welsh underground artists of Brigyn songs.
Brigyn achieved prominence in the media through successfully obtaining the permission of Leonard Cohen to release a Welsh-language version of his1984 song 'Hallejujah'.