In the first round, each contestant is asked four (or occasionally three if there is a shortage of time) questions, two of which are illustrated by short musical pieces.
Five categories of questions are offered, some of which are very specific e.g. "Beethoven's Piano Sonatas", while others are more general, for instance "sunshine and rain".
The show has been broadcast in BBC Radio 4's Monday afternoon quiz slot since 1998 with a repeat on the following Saturday evening.
Russell Davies hosted the programme between November 2013 and October 2014 after Gambaccini was arrested on suspicion of historic sexual offences.
The original theme tune for the programme, when it began in 1986, was The Arrival of the Queen of Sheba by Georg Friedrich Handel.
In the late 1990s it was opened by a specially commissioned piece entitled "Counterpoint", by musician Ray Davies.