Veszedelmes labdacsok (1967)

Evelyn chased by gangsters accidentally run straight into the arms of Templár Simon. She asks him to find out who killed her uncle Arthur, the inventor. It quickly becomes apparent that he had to die because of some pill like balls he invented. There are three different balls: the first makes one invisible, the second turns man into woman and woman into man, and from the third one everyone sings uncle Arthur's unreleased hits.