I was wondering if different people with Syntheasia have the same associations or does it appear to be random? Like, if two people had shapes and music crosswired, would they associate the same set of shapes with the same set of music or would it be different?
The composers Nikolai Rimsky-Korsakov and Alexander Scriabin had different tone-color associations, though Scriabin’s claim that he experienced actual synesthesia is in dispute.
I believe I once read of an argument between Rimsky-Korsakov and Scriabin over these sound/color associations, witnessed by Prokoviev, IIRC, who didn’t understand what they were arguing about.
If you’re asking whether all synesthetes see Tuesday as green, or the number 3 as loud, the answer is apparently no. I don’t have a cite, but I was curious about this myself, and researched it before.