Guitar friendly keys

What is a guitar friendly key? A guitar friendly key is one that allows a player to do two things. First, it lets him or her use lots of open strings, something which can make playing a bit easier. If you look at the diatonic notes in the keys of G major, D major, and C major, you can see that every open string (top to bottom: E/A/D/G/B/E) is a diatonic note in these keys.

A guitar friendly key is also one that is easy to recognize at various postions on the neck, since important notes of the key (root/tonic/etc.) fall on a guitar's marked frets. The marked frets on a guitar, with their corresponding notes, are:

Fifth fret, bottom to top string: A/D/G/C/E/A

Seventh fret, bottom to top string: B/E/A/D/F#/B

Ninth fret, bottom to top string: C#/F#/B/E/G#/C#

Tenth fret (if you have a European made guitar), bottom to top string: D/G/C/F/A/D

Twelfth fret, bottom to top string: E/A/D/G/B/E

If we examine the key of D major, we can see that three (or possibly four) of these fret positions have the root note "D", and three (or possibly four) have D major's dominant tone "A." If we look at the key of G major, we can see that two (or possibly three) of these positions have the root note "G", and three (or possibly four) have G major's dominant tone "D." These marked frets provide visual cues which allow a player to navigate more quickly and confidently on the neck when switching positions. A large number of the tunes Django played were in the key of G major, a very guitar friendly key. A partial list of these tunes includes Sweet Sue, Lady Be Good, Hungaria, Nuages, Dinah, I Can't Give You Anything But Love, and Confessin'.