Kongos

Alternative rock music with a little world-ish flair.  They have one relatively big hit (Come With Me Now) that has some New Orleans accordion like a Graceland track, but then the rest of the song like a hard-rockin', hand-clappin' Mumford singalong with Imagine Dragons.

Listening to the rest of the album, they've got a reggae tinged tune, some more straight-forward rockers, a ballad or two, and then one with some serious Gypsy accordion solo action.  According to Wikipedia, the band is four brothers with the last name Kongos, who are originally from South Africa, then London, and now live in Arizona.  Must be a bummer to end up in Arizona.  I dig the family band mystique though - likely hard to pull off, but if you can do it I bet it is really fun.  I have a feeling that the accordion playing brother is going to get booted out of the band soon so that they can go more mainstream and quit having weird accordion solos in all their music.

Their other hit is called I'm Only Joking:

I had not heard this one before, but for rock music featuring an accordion its actually good.  Kind of dark but stuck in my head pretty well afterwards.  The full album (Lunatic) is a pretty good time.  I think I like these guys and will go check them out, depending on the schedule.