Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Roland MC-303 is the first of a series of musical instruments known as a Groovebox. It combines a simple sound module with a sequencer to record and store notation, along with controls aimed at encouraging the musician to improvise the music while it is playing. Despite the number in its name and the hype it received at its launch, the MC-303 has more in common with other MC prefixed synthesizers (such as the Roland MC-202), which contain built-in sequencers, than it does with the famous Roland TB-303.