The Nashville or hi-strung guitar uses the strings that would remain from a 12 string set if the 6 regular strings of a normal 6 string set were removed. That is, they are the octave higher strings of the bass E, A, D, G, and then regular gauge B and high E. The octave G makes it sound very much like a 12 string and yet the sound is more transparent without all the deep bass. This makes a great rhythm guitar or second rhythm guitar sound and is heard on many recordings.