Most recorders nowadays are in the keys of C or F, plus the G alto. But what about other keys? I've seen a video on Youtube of a "tenor" recorder that was supposed to be in the key of B flat, but due to A-415 tuning was really in the modern key of A (in which case it probably should be called a baritone recorder instead of tenor). Sorry but I can't find the link anymore!

I've always wanted to find out if there's such a thing as the mezzo-soprano recorder, which would presumably be in the key of A or A-flat, in between the soprano or tenor. If so, what would the tone color be like?