i've been told that folk music is a type of music that many folks simply won't listen to / that's also true of opera, and i'm sure opera exits. so it's likely that folk music exists as well.

Folk isn't quite the same as Opera in that it was only perceived to exist by those learned few who defined it as such from their lofty position of would-be erudition. Thus Folk is a theoretical construct founded on the flimsiest of pretexts with much of the evidence being falsified if only to prove a point. This situation is further compounded by those who having convinced themselves that Folk is somehow real, then go on to define it (see 1954 and All That) according to an immovable theology which only dangerous heretics dare question in fear of their very lives. Thus Folk Music is, somewhat perversely, no longer the reserve of The Folk, but of a highly specialised pseudo-academic race of Dementor-like beings who speak of a Holy Mystery known as The Folk Process, which in any case, as they'll tell you, no longer exists. Thus do they suck the very life out of the music, not content until it is all safely gathered in, cut, dried, stamped, indexed and filed away never to be heard by the actual Folk again, who in any case would rather be watching TV.

Meanwhile, out here in the real word, even Operatic Arias are sung as Folk Songs by The Folk. But don't tell the Folk Dementors that or else they'll suck your soul out through your arse.