while adding a bit of heart and unsettling subject matter 
(ROOT (PP (IN while) (S (VP (VBG adding) (NP (NP (NP (DT a) (NN bit)) (PP (IN of) (NP (NN heart)))) (CC and) (NP (JJ unsettling) (NN subject) (NN matter)))))))
(ROOT (PP (IN ) (S (VP (VBG ) (NP (NP (NP (DT ) (NN )) (PP (IN ) (NP (NN )))) (CC ) (NP (JJ ) (NN ) (NN )))))))