G

G is one of the most popular guitar keys — the open G chord rings with all six strings. G major's single sharp (F#) makes it accessible while still sounding full and resonant.

G major is the key of Beethoven's Fourth Piano Concerto and countless folk, country, and pop songs. On the guitar, the open G chord's voicing spans all six strings, giving it a rich, full sound that has made it a campfire staple.