Definition from Wiktionary, the free dictionary
A-flat (plural A-flats)
- (music) A tone four fifths below C in the cycle of fifths, intermediate between G and A, denoted A♭.
- The bassoon came in on a low A-flat.
- (music) A key or other mechanism for producing an A-flat.
- I had to take it to the shop because the A-flat was stuck.
- (music) The key of A-flat major.
- We will now hear the third sonata, in A-flat.
tone four fifths below C