One thing that I was taught by Rick Fielding (and I am still pretty much a novice) was to lower the strings (to what I guess would be an open E tuning)if I was going to sing ballads or other similar songs with a banjo -- this cuts the brassiness, and makes it easier to sing with, I find. (Heather Fielding still sells Rick's banjo mutes, though I have been using a sock, mostly).