The diagrams below show all of the dominant seventh chords. (Such chords are usually just called seventh or 7th chords.) Use notes 1 - 3 - 5 - b7 in a particular key to create the chords. For an explanation of the figures, go to the notation file. To understand how the chords are derived, go to the tutorial on keys. Table 3 is a quick summary of how chords are formed, and Table 2 contains all the notes in all of the (major) keys.
The "A7 form", "D7 form", etc. notation means the form can be moved along the guitar's neck. That is explained further in the Bar Chords section.
