Final answer:
A perfect fifth below A-flat (P5 down Ab) is the note D-flat.
Step-by-step explanation:
A perfect fifth below A-flat (P5 down Ab) is the note D-flat. A perfect fifth is an interval of seven semitones or half steps. Starting from A-flat, count back seven semitones, and you will reach D-flat. In a musical scale, the perfect fifth is an important interval that creates a sense of stability and consonance.