This character is a bass player.
A bassist is a musician who plays a bass instrument such as a double bass, bass guitar, keyboard bass or a low brass instrument such as a tuba or sousaphone. Different musical genres tend to be associated with one or more of these instruments. Since the 1960s, the electric bass is the standard bass instrument for rock and roll, jazz fusion (and occasionally other forms of jazz), heavy metal, country, reggae and pop music. The double bass is the standard bass instrument for classical music, bluegrass, and Swing-era and Bebop-era jazz. Low brass instruments such as the tuba or sousaphone are the standard bass instrument in Dixieland and New Orleans-style jazz bands.