Complex sentence: Stillness Breathes 1991--2006 is a double disc compilation album by the band Mercury Rev. Disc one compiles tracks from their first six studio albums, while disc two consists of covers, B-sides, and previously unreleased tracks.
Split into simpler sentences: Stillness Breathes 1991--2006 is a double disc compilation album by Mercury Rev. Disc One compiles tracks from their first six studio albums. Disc Two consists of covers, B-sides, and previously unreleased tracks.