musical synasthesia?

I recently sent this email to someone who asked me about my experience of this phenomenon/condition, along with sub-queries on a particular (though theoretical) key and 'sadness' in music.

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My synasthesia is not very strong. I don't usually see colours when I hear single notes, but more when I get harmonic impressions. Sometimes I might get a weak colour sensation from a single note, and it will tend to be the colour of that note's major key.

It's definitely the case that people with synasthesia experience colours differently - I read about Scriabin's very pronounced condition and many of the colours were different to mine.

"G sharp major" does not really exist for me, since I would hear it as A flat major. That is a dull, but rich red with hints of purple. (I'm not sure what I would see in the almost inconceivable case that someone was in B major and then modulated through sharp keys all the way to G sharp major!)

"Sad keys" are partly determined by musical context. All the minor keys are potentially sad. Perhaps I could say that E flat minor and B minor are particularly "sad", while G major, A major and E major are particularly "happy" (I omit D major from that list because it seems richer than "happy", but this is leaving the question of colours somewhat). Here's a non-systematic and incomplete list of impressions...

Greens come from E, E flat, G and G flat
Yellows come from B and D
Reds come from A, A flat and F sharp minor (F sharp major is like arainbow, with orange emphasis)
F minor is ivory and purple, sometimes pink
C minor is black, dark brown, also gun metal, and other things hard toput into words (C major is like a shiny version of that, or sometimes can be matt, like peat)
B flat is almost white; the minor is grey
D flat is almost colourless, but also sometimes off-white
C sharp minor is impossible to put into words! But I love it.

colour is not sitting still

For some reason it is easier to understand this idea of electromagnetic waves actually altering what they touch when you are talking about invisible ones like x-rays. It is hard to believe that light - lovely friendly white light - also changes almost every object it hits...

The best way I've found of understanding this is to think not so much of something 'being' a colour but of 'doing a colour'. The atoms in a ripe tomato are busy shivering - or dancing or singing; the metaphors can be a joyful as the colours they describe - in such a way that when white light falls on them they absorb most of the blue and yellow light and they reject the red - meaning paradoxically that the red tomato is actually one that contains every wavelength except red.

Victoria Finley, Colour: Travels through the Paintbox (Sceptre, 2002), page 6.