A-flat minor is rarely used as the main key of a piece of music.
More often, pieces in a minor mode that have A♭ as the tonic are written in the enharmonic key, G-sharp minor, because it has a simpler key signature. Because of this, there are few works in A-flat minor.
In some scores, the A♭ minor key signature in the bass clef is written with the flat for the F on the second line from the top.
An early section of the last movement of Beethoven's Piano Sonata No. 31, Op. 110 (although the key signature of this section uses only 6 flats, not 7)