In the same way you're supposed to do pilates or something to stop yourself becoming a hunchback with a slipped disc, I think every illustrator should join a choir! (I mean, ideally every human being would, there'd probably be fewer wars and more shared cakes.) Singing in Lichfield Gospel Choir is basically the exact opposite of what I do on an average day in the studio; instead of sitting at my desk, alone, covered in little bits of paper and glue, serenading my dog, I stand in a school hall and sing for two whole hours with about seventy other lovely people, led by our brilliant musical director, Themba Mvula. It's enough to make a freelance illustrator positively giddy.
I've been a member for just over two years, have finally learned all the words (quite a lot in Zulu), and can now both clap and sing at the same time without a look of extreme concentration (I think). There is nothing better than choir practice on a Tuesday evening to make the world feel like an exceptionally glorious place.