From Longman Dictionary of Contemporary Englishsignature tuneˈsignature ˌtune noun [countable] British English TCBAPMa short piece of music used at the beginning and end of a television or radio programme
Examples from the Corpus
signature tune• Even the distinctive signature tune has been re-recorded to provide a more modern feel.• One thing I regret: the jettisoning of the original signature tune.• It was Buddie's signature tune, the one his band always played at the start of every session. 