With respect to why some acquired savants are musical, and some are good at the arts, and some are mathematical, why aren't they all the same; I think that has to do with this genetic endowment that all of us have.
The ways in which acquired savants show up are usually the same ways that congenital, or non-acquired, savant syndrome shows up. They tend to show up in the same areas: music, art, math, visual, spatial skills, and calendar calculating, although calendar calculating probably isn't quite as prominent in that group. They tend to show up quite quickly, or sort of explode on the scene and they then tend to have an obsessive sort of forceful quality about them in the same way as savant skills. So they tend to show up in the same ways.
There are people at the extremes who aren't able to do anything musically, and then others sort of fall in the middle. And the same thing with math, and the same thing with art. You'll find people who are geniuses, or prodigies at the far end of the bell shaped curve, and I think you will find some of the acquired savants in that category who happened to have been endowed with that kind of talent, which explains why not everyone becomes an acquired savant.
