What a great set of responses! Guest, you said it best... defining the difference between beat and rhythm. Even speech can have rhythm. There is an internal rhuthm in many words. I was talking more about beat than rhythm.

And, in my rush to start this thread before heading out the door this morning, I didn't mean to "define" or limit what I think of as folk music. Maybe just as well that I didn't express myself well. Part of the fun in a conversation is to be challenged to focus your thinking.

I think Johnny Cash's song really is saying Get the beat. Even ballads have some rhythm to them (or they're likely to end up putting you to sleep.)

And of course, much of folk music was for dancing. Seems to me that Kevin McGrath made a statement that all folk music is for dancing (which is beyond what I would agree with.) It's not just the obvious string band/fiddle tunes/and accordians/tin whistles and all the rest.
If any song has an infectious rhythm, you'll get people dancing.

This morning, I was rushing out because my group had been asked to sing at a funeral service in Brooklyn (a 2 and a half hour drive from here.) The service was held in a funeral home and because the woman was well into her 90's, there weren't many friends left to say goodbye and the room was only modestly filled. I had brought my electric guitar, and we were going to do three songs that had been requested. But, because there was a major accident on the highway, everything was running late, so we cut it down to two songs, and because of the smallness of the room and the seriousness of the occasion, we ended up doing the songs a capella. This contrasts with the first funeral we sang at a few years ago, where we did some upbeat songs in a black church, and people were dancing in the pews and in the asiles. We were standing with our back against the coffin, and everyone was having a good "home going" celebration. In both instances, there was a rhythm to the music, but there was a strong beat to the more "upbeat" songs we did at the black church.

Got Beat?

Jerry