39.60Level 33 — ♯9/♭3 relationship

This terminology depends on context.

Over F7:

A♭ may be heard melodically as:

blue ♭3

or enharmonically as an altered ♯9-type dominant color.

For blues playing, ♭3 is usually the more intuitive melodic concept.

For chord-extension analysis, ♯9 can be useful.

Same piano key.

Different conceptual lens.