one of the most wanted sounds in electronic music, rivaling the tr-808, tr-909 and several
moog synths. It was supposed to sound like a real bass guitar, which it totally sucked at. so roland, the manufacturer, stopped making them pretty quickly, so they're kinda rare. after that, house Djs in the 80's started messing around with them (Dj peirre?) and found that you could make some
pretty wild sounds with them. 303s eventually came to form their own style of music Acid, where
the 303 is in basically every song, or at least another synth trying to sound like a
303.