On their fourth full-length release, San Diego's Buck-O-Nine continue to trace the ska-punk revolution from its '70s roots to its '90s incarnation. With a robust horn section bopping alongside their breakneck reggae rhythms, Buck-O-Nine's lead singer Jon Pebsworth struts his stuff in a voice that would make Joe Jackson proud. While the punk spirit on this CD is often eclipsed by the band's feel good melodies, Libido is still an extra-energetic foray into modern ska. Jonas Kleiner's guitar playing is both upbeat and tasteful on fun tunes such as "On a Sunny Day." With some tranquil moments and world music creeping into their overall sound, Buck-O-Nine show they aren't afraid to experiment with the ska-punk formula. --Mitch Meyers