derailed by a failure to seek and strike just the right tone 
(ROOT (S (VP (VBN derailed) (PP (IN by) (NP (DT a) (NN failure) (S (VP (TO to) (VP (VP (VB seek)) (CC and) (VP (VB strike) (NP (RB just) (DT the) (JJ right) (NN tone)))))))))))
(ROOT (S (VP (VBN ) (PP (IN ) (NP (DT ) (NN ) (S (VP (TO ) (VP (VP (VB )) (CC ) (VP (VB ) (NP (RB ) (DT ) (JJ ) (NN )))))))))))