Rags?

Hi all

Recently I blundered into a jam with 4 accomplished fiddlers, a bass and rhythm guitarist.  They proceeded with an hour of "rags" in C.  I play a melodic clawhammer with few chords or brush/strums, the usual OT fare and some contra dance tunes.  I was lost.  I don't know rags. These folk are all friends and were not abusing me, but they went into tunes/directions I had never heard.

Any orientation thoughts, links, reads or listens on how a melodic clawhammer does "rags".  I guess I mainly just don't know this music, it's rhythm or cadences.

Thanks