Complex sentence: Tarsia decided to run Jackson's bassline through a phaser, giving it a swishing sound--and during the final mixing of the track, Kenny Gamble impulsively reached over to the echo button and added an echo effect to Jackson's opening riffs.
Split into simpler sentences: Tarsia decided to run Jackson's bassline through a phaser, giving it a swishing sound and later mixed in echo. During the final mixing of the track, Kenny Gamble impulsively reached over to the echo button and added echo to Jackson's opening riffs.