Get Smart (1965)

Season 1: Episode 26

Max and the Chief disguise themselves as concert critics as they go in the aid of Hubert, a violin virtuoso who has been working undercover to find the identity of KAOS's Big Boss. Just before Hubert is able to give his report he is killed but first hides a clue in the form of writen music. Max must then stop pianist Wolenska from being killed by a bomb planted in the piano on which he will perform Hubert's last symphony, a desperate attempt of the Big Boss to keep his identity secret.