I have two 6-stringers (one std., one baritone) but they are strung in 3 pairs, not like a guitar (the nuts aren't notched to allow 6 equidistant strings). Some modern 4-stringers have extra notches to accommodate equidistant stringing & tuning. My Std. 6 (a McSpadden "Schnaufer 6") is tuned (from low to high, dD-aa-dd, with the lowercase being the octave unwound string); my baritone 6 is tuned dD-aA-dd. They sound like 12-string guitars (or the std. one more like a Nashville high-strung guitar), except for the fact that one pair almost always rings out as an unfretted drone.........which is why they're NOT guitars.