Sound Tribe Sector 9's live shows seamlessly dissolve instrumental musings into fine-tuned sonic sculpture, veering from lengthy, jazz-driven improvisations to laptop-enhanced downtempo suites. The Santa Cruz-via-Atlanta quintet's 2005 album, Artifact, combines the best of both sides of the band, charging warm-and-fuzzy acoustic guitar and elegant piano with sinister breakbeats and deep-space atmospherics. Occasional appearances from drum 'n' bass diva Audio Angel add instant soul to an album of chilled-out head food, smearing hip-hop and late-night jazz onto STS9's diverse palette. Seventy-some minutes alternate between dense and spacious, bubbly and sharp, vintage and cutting-edge, sometimes in the same song (check "Tokyo," the monumental single). Bringing to mind the masters of moody electronica (LTJ Bukem, Wagon Christ, K&D), the self-produced Artifact is aptly titled, providing a brilliant snapshot of a band in constant evolution.