on a group of extremely talented musicians 
(ROOT (PP (IN on) (NP (NP (DT a) (NN group)) (PP (IN of) (NP (ADJP (RB extremely) (JJ talented)) (NNS musicians))))))
(ROOT (PP (IN ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (ADJP (RB ) (JJ )) (NNS ))))))