Complex sentence: In 1951, computer music including music sequence, music composition and sound generation were started, however, RCA Mark II Sound Synthesizer in 1957 was still indirectly controlled via punch-tape system similar to piano rolls.
Split into simpler sentences: In 1951, computer music (including music sequence, music composition and sound generation) was started. However, the RCA Mark II Sound Synthesizer was still indirectly controlled via punch-tape system in 1957, similar to piano rolls.