Them forged their hard-nosed R&B sound in Belfast, Northern Ireland, moving to England in 1964 after landing a deal with Decca Records. The band's simmering sound was dominated by boiling organ riffs, lean guitars, and the tough vocals of lead singer Van Morrison, whose recordings with Them rank among the very best performances of the British Invasion. Morrison also wrote top-notch original material for the outfit, whose lineup changed numerous times over the course of their brief existence.