Well, if he likes any kind of music, there is some bastardization of it that hyphenates with folk.

As in, folk-rock, folk-blues, or as they say nowadays folk-roots, folk-punk, country-folk, folkabilly, jazz-folk-fusion, folk-rap (a few instances of this exist) and there are folk operas.

If he's into disco, forget him.

If he likes classical, well, so do lots of folkies.

Tell us what he does like and we can tell you whom you should force him to listen to.

W-O