Thematically and stylistically, "Let There Be More Light" and "Set the Controls for the Heart of the Sun" are bookend tracks, but in every way, "Set the Controls for the Heart of the Sun" is more successful. Right down to the science fiction lyrics, this song (like much of A Saucerful of Secrets) maps out the style of progressive rock that would eventually be dubbed "space rock." Specifically in this case, the long, flowing keyboard and guitar lines and Roger Waters' whispered vocals are completely in keeping with what would become the hallmarks of the style. However, it's the other elements of the arrangement that make this the strongest song on A Saucerful of Secrets, particularly Waters' pulsating bassline, which carries the entire song, and Nick Mason's shimmering vibraphone accents and faux-tribal drumming, which add an unexpected jazzy depth to what otherwise could have been a fairly standard-issue piece of sci-fi psychedelia and makes it more of an obvious precursor to Can's polyrhythmic explorations than Kraftwerk's rigid Apollonian tendencies. As the lengthier and noisier live version on Ummagumma attests, "Set the Controls for the Heart of the Sun" remained a staple of Pink Floyd's live show for years, and became the basis for some of their more effective improvisations.