Question: Is there a seven string guitar?

Answer: Yes, there are seven string acoustic guitars. You tune the lowest string (7th) to the next B below the bass E string.

Bob, Gman ( o )==#

There's also a long 7-string tradition in Russian guitar playing, probably a bit older, or at least more common in the 19th century, than the 6-string tradition; the tuning was mostly in 3rds, so that the low string was D (one step below our 6th string E), and the first string was also d (one step below our 1st string E). Nice G-major tuning. (DGBdgbd). Oleg Timofeev has some CDs out with some of the 7-string guitar music.

Coste, and some other classical players in the 19th century, also had a seventh string (some had more, 10 or 11 being more common than 8 or 9, but only the lowest 7 had frets available for stopping the string). The seventh string was tuned to D below E. This means that some of their works are awkward to play: either we retune, and "mess up" some otherwise reasonable fingerings, or retain the fingerings (and hand shapes for chords) and lose access to the low D. While not exactly common, non-6-string guitars were more common then than now.

Later.

Tim Beasley