To some folks, if a song is "very recently written," it ain't folk.

A completely traditional repretoire is fine, *IF* the performer has the talent and creativity to bring some kind of fresh approach that effectively "keeps the tradition alive" by renewing/reinterpreting well-known numbers that *could* be old and tired in less capable hands.

The availability of a traditional "database" of well-known tunes is absolutely necessary for group sessions or jams, especially those that welcome newcomers.

For solo performers (self-accompanied singers), on the other hand, it's more important to be able to offer something new -- new arrangements and interpretations of familiar favorites, at least, if not completely new compositions.