Major 7th chords (maj7) are commonly used in place of plain major chords. The formula for a Maj7 chords is Root-3-5-7. In the key of F this would be F-A-C-E. In the key of Bb it's Bb-D-F-A. Practice spelling Maj7 chords for the other ten keys.
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Minor 7th Chords
Minor 7th chord (min7) are common replacements for plain minor chords. The formula for a minor7 chords is Root-b3-5-b7. In the key of G this would be G-Bb-D-F. In the key of D it's D-F-A-C. Natural signs will be used in these examples to show when sharped notes are naturaled for note b3 or b7. Practice spelling the min7 chords in the other ten keys.
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Dominant 7th Chords
Dominant 7th chords (7), sometimes simply refered to as "dominant" play a very important role in chord progressions. You will be learning about this in great detail in the intermediate book of this series. For now, it is enough to know that the formula for a 7 chord is Root-3-5-7. It has a natural 3, like a major chord and b7 like min7 chord. In the key of E it is spelled E-G#-B-D. In the key of A it's A-C#-E-G. As you have done with the other chords, practice spelling these in all keys.
