The advice to Tone d'F is based on the idea that the music is incidental to an activety that has a licence - the bar.   This is interesting except of course that the DCMS refused to define incidental and said it was a matter for the courts to interpret. Advertising may render it "non-incidental" or may not but it is more than odd that a serious peice of legislation like this results in music being half hidden, as if it were a subversive plot!