Jon - generally American old-time country string bands use 5-string banjos. The Tenor(or is it plectrum?) seems to be used in jazz & ragtime bands.

The 5-strings were played in a variety of clawhammer/frailing styles until Earl Scruggs came along and introduced 3-finger picking. That's not to say that there weren't some tenor players in country, just not very common.

Charcloth - what tuning/s do you use for 6/8 clawhammer, and what are some of the jigs you play? I want to experiment.