Want to play the opening riff to “Smoke on the Water” on a 3-string cigar box guitar tuned to Open G GDG? Just use your index finger to “bar” (hold down) all three strings, and move it as follows while strumming:
Open / 3 / 5 / Open / 3 / 6 / 5 / Open / 3 / 5 / 3 / Open.
You can also sing along! DAH DAH DUHN, DAH DAH DAH DUHN, DAH DAH DUHN, DAH DUHN (dundundundun).