Oscar had a stroke, which he didn't really recover from -- he just played mostly one-armed.

I just saw this incredible video [1] last week about him and "the greatest solo ever recorded."

[1] https://www.youtube.com/watch?v=yj93v9j2A4A

Great video. Note the signature on that guitar by the way (2:49).

One more: Edwyn Collins, from Wikipedia:

In February 2005, Collins was hospitalised after two cerebral haemorrhages which resulted in aphasia, and he needed months to recover. He resumed his musical career in 2007. A documentary film on his recovery, The Possibilities Are Endless, was released in 2014.

Judith Durham, Australian singer and songwriter famous with The Seekers in the 1960s but active ever since, had a stroke.

Afterwards she could still sing but had lost the ability to write songs.

Agraphia is an impairment or loss of a previous ability to write.

I can read fine. I can type fine. Drawing is mostly fine. Physical writing is total gibberish. Think severe alzheimer level.

For Judith Durham, I don't know if the problem is the physical writing of the songs, or the ability to compose a song. Sources aren't clear on that.

Well Kirk was cheating because he could just play the other sax.