Complex sentence: The tunes played by the Dixieland band, Pete Kelly's 7, are played by a grand assortment of Dixieland musicians, among them Dick Cathcart (cornet/trumpet).
Split into simpler sentences: The tunes played by the dixieland band, Pete Kelly's 7 are played by a grand assortment of Dixieland musicians. Among them Dick Cathcart (cornet/trumpet).