What's that noise?

Every half-hour, the foghorn in the lighthouse would go off. Over the years, the lighthouse-keeper grew accustomed to the sound and even fond of it.

One night, at four-thirty in the morning, the foghorn failed to sound. The lighthouse-keeper immediately woke up and jumped out of bed, yelling "What's that noise?"

A childrens television show aired on BBC1 about music. The idea was to get children to appreciate different kinds of music, not just the mindless dribble which was in the charts at the time (and most likely still is). They would have different types of artists and music on the show and would highlight the differences of the genres, have interviews, and such.
Was hosted by Craig Charles (of Red Dwarf fame). First shown in the early 1990s, iirc