I passed the standard grades with top marks in computing and music

Ironically, those are two subjects that are intensely based on mathematics. Programming, music, and physics are all just different (or not so different) aspects of applied mathematics.

I don't want to argue, but you don't really need any math for most of the fields in music. To perform music on an instrument - you do not need mathematics, to conduct - you do not need mathematics, to compose - you still do not need mathematics, maybe the closest thing where you need to "think mathematically" is harmony - but still you don't need to know math to harmonize a melody - you just need to know a set of rules an be creative sometimes. In music you need fine hearing, creativity, and musical intuition. Music is art, mathematics is science. So there's nothing ironic, really.

Telling somebody to use a pentatonic scale over a I-IV-V progression is kind of the same thing as telling somebody to use arctangent to get the angle between two vectors. There is lots of math going on as to why they work but you don't have to understand any of it to use it (but you should understand it).