Once is the fifth studio album by Finnish symphonic metal band Nightwish, released on June 7, 2004 by Nuclear Blast, and the last to feature Tarja Turunen on lead vocals. In an interview, Tuomas Holopainen (main song writer of the band) said that it is up to the listener to find out the meaning of the title Once. Every name has a meaning — though, he doesn't feel comfortable talking about it.