I'm a staunch advocate of the 7 String Guitar. I asserts that solo guitar music can be best woven adequately in a 7 strings. I stress that the added string renders a potentially wider tonal range and by lowering the 7th string gives us the low note-tuning desired to fulfill a transcription or arrangement. I maintain that in a 7 String Guitar, a player can still wrap the left hand thumb around the top of the finger board if needed, to adapt to playing styles other than classical.