Complex sentence: Caspersen started playing bass when he was twelve; for his 12th birthday he bought a bass (his first) instead of a planned bicycle, because a lot of his friends were in bands, Victor Wooten, Les Claypool and Alex Webster as his biggest influences.
Split into simpler sentences: Caspersen started playing bass when he was twelve; for his 12th birthday he bought a bass (his first) instead of a planned bicycle, because a lot of his friends were in bands. He cited Victor Wooten, Les Claypool and Alex Webster as his biggest influences.