On their fourth album, 1981's "BGM," the Yellow Magic Orchestra picked up the thread of its predecessor, "Xi Multiplies," going deeper into the realm of synthesizers and drum machines and experimenting with rhythm, speed, and sequences. This album focuses on atmosphere and mood. Some fans say that the album marks a turning point in the relationship between YMO and the international pop scene. On "BGM " the band successfully mixed lyrics, sound snippets and their signature electronically programmed music. "1000 Knives" and "Cue" are the most famous tracks, while the clapping on "1000 Knives" is certainly one of the most sampled sounds ever.