Les Paul fretboard
Jimi Hendrix playing the guitar on stage Marjut Valakivi / Public domain
Guitar player playing guitar chords by number
Warren Haynes - Soulshine songwriter and founding member of Govt Mule pitpony.photography [CC BY-SA]
John Frusciante of Red Hot Chili Peppers playing guitar Flickr photographer Chad Carson [CC BY-SA 2.0], via Wikimedia Commons