There is more than one artist with this name: 1) Firefly were a one-off project comprising San Francisco soul/dance singer Krystle Jones and former My Life With The Thrill Kill Kult member Dave Dasher. Their album, The Big 8 Double Golden, was released independently in 2005. The sound combines funk, soul, house, and 70s disco. 2) Firefly are a musical trio, hailing from Lisburn in Northern Ireland, who play rock music with punk overtones.
Firefly are licenced to the world via audio-ill.

Read more about Firefly on Last.fm.