sleepy.ab is a four-piece post-rock band from Hokkaido, Japan formed in April 2002. They describe their music as having characteristic melodies of transparency and floating aimlessly. The "ab" in their name stands for "abstract", and it isn't pronounced when spoken. sleepy.ab members are: 成山剛 (Tsuyoshi Nariyama) on vocals/guitar , 山内憲介 (Kensuke Yamauchi) on guitar, 田中秀幸 (Hideyuki Tanaka) on bass guitar, and 津波秀樹 (Hideki Tsuha) on drums. They've so far released four studio albums, one compilation album, and two limited release live albums sold only at shows and through their online store.