That's a good question for your oncologist @Blondy
It seems the variations on what can go pear shaped after chemo are pretty much endless. TC in particular is very hard on tendons, ligaments and muscles and, reading the posts here, it is very common for things to deteriorate some weeks after treatment ends.
If there was anything wrong with my voice post chemo I'd have to had put it down to my endless whining about all the other aches and pains. As a singer the muscles in your throat would be more developed than most of us, but it is worth getting checked out to make sure you don't have some sort of infection lurking in the background. Mxx