whose valuable messages are forgotten 10 minutes after the last trombone 
(ROOT (SBAR (NP (WP$ whose) (JJ valuable) (NNS messages)) (S (VP (VBP are) (VP (VBN forgotten) (PP (NP (CD 10) (NNS minutes)) (IN after) (NP (DT the) (JJ last) (NN trombone))))))))
(ROOT (SBAR (NP (WP$ ) (JJ ) (NNS )) (S (VP (VBP ) (VP (VBN ) (PP (NP (CD ) (NNS )) (IN ) (NP (DT ) (JJ ) (NN ))))))))