who is not only a pianist , but a good human being 
(ROOT (SBAR (WHNP (WP who)) (S (VP (VBZ is) (CONJP (RB not) (RB only)) (NP (NP (DT a) (NN pianist)) (, ,) (CC but) (NP (DT a) (JJ good) (JJ human) (NN being)))))))
(ROOT (SBAR (WHNP (WP )) (S (VP (VBZ ) (CONJP (RB ) (RB )) (NP (NP (DT ) (NN )) (, ) (CC ) (NP (DT ) (JJ ) (JJ ) (NN )))))))