Quartetto Gelato is a classical music quartet from Canada that includes an accordion and an opera singer. They play fun music (which isn’t to say that they are doing easy music or playing sloppily). They also do some freaky fun staging. They have been known to do a lot of Italian music (hence the name).
I’ve had their second album, Rustic Chivalry, for ages, and there are times I’ve just played it nonstop. Their lineup has changed since then, but the group itself seems to be going strong.
They’ve got a fair number of pieces up on YouTube, so check them out.