I am synaesthetic

I have synaesthesia. Colour-Sound synaesthesia to be precise. Meaning that when I hear sounds and music I "experience"/"see" colours and shapes in my head/mind/mind's eye. Each song and instrument and sound will have it's own unique shape(s) and colour(s) that obviously "play out"/"occur" over time, just as the sound/song itself does. It is quite hard to explain.

I also have a very vivid visual imagination.

So when I am giving comments and feedback on songs, I may also share my synaesthetic experience, and try to describe what shapes and colours your sounds/songs have. That is why I may say things like "it is a very purple tune" or "I am seeing a rich green valley" etc.