while the performances are often engaging 
(ROOT (SBAR (IN while) (S (NP (DT the) (NNS performances)) (VP (VBP are) (ADVP (RB often)) (ADJP (VBG engaging))))))
(ROOT (SBAR (IN ) (S (NP (DT ) (NNS )) (VP (VBP ) (ADVP (RB )) (ADJP (VBG ))))))