Finally something I can answer in this thread. G sharp and A flat are the same tone. They look differnt on paper, but are indistinguishable to the ear.Maybe this is ‘way off topic, but I think (may be wrong…) that G-sharp and A-flat are the same note on a piano. In vocal music, they may vary slightly depending on the basic key (as in well-tempered… et al.)
Ah, my work here is done.