A-flat minor is also used in Frederick Loewe 's score to the 1956 musical play My Fair Lady ; the Second Servants ' Chorus is set in A-flat minor . It is also used in Frederick Loewe 's score to the 1956 musical play My Fair Lady ; the Second Servants ' Chorus is set in A-flat minor ( the preceding and following choruses being a semitone lower and higher respectively ) .