"You can play folksong with two guitars, three guitars, a guitar and a banjo, guitar, bass and mandolin, or whatever. It's not like so-called "classical" music, where the instrumentation is usually specified. "

Yes. We did start by trying songs together and all three of us have been rather blank -- I think both guitarists may be used to either playing ready-made solos or accompanying a singer individually. That's why I thought it may be helpful to start with listening to a recording which already has two guitars, and playing that song to feel out playing together. Not a good idea?