I've started playing around with non-standard(?) ways to tune the fifth string. For example, in open G I've never liked the sound of the fifth string when playing a D chord on some pieces. Lately, for some tunes ( e.g. Long Steel Rail, Pretty Polly, and Nora Lee ) I've been tuning the banjo to DDGBD and DDGCD. I think it sounds good -- the thumbed fifth string D ( the ty part of the bum-dit-ty) doubled up with the identical note on the first string( the dit part of the bum-dit-ty ), for example, is pretty cool. I don't know that it would work for all possible tunes, probably not.
Also, for some reason I can't explain, the fifth string seems more harmonious with all 3 chords G, C, and D, than the fifth string tuned to G sounds. I can't explain that rationally, since adding D to the C chord should sound just as weird as adding G to the D chord, but to my ears a CDEG ( C add 9? ) sounds better than a DF#GA ( D add 11? ) .
Am I just kidding myself? Is this kind of insanity officially sanctioned by the banjo players' union?