About the A7 Baritone chord
Play A7 on Baritone ukulele with the 2 2 2 3 shape in DGBE tuning.
Use your index finger to barre the 2nd fret across the D, G, and B strings. Place your middle finger on the 3rd fret of the E string. Strum all four strings and check that each one rings cleanly.
Read the frets across D, G, B and E. A 0 means open and x means mute. These fingerings are for Baritone strings. A Standard gCEA chart uses different shapes for the same chord names.
Root
A
Quality
Dominant 7th
Notes
A · C# · E · G
How the A7 chord works
A
Root (1)
The home note. It gives the chord its name.
C#
Major third (3)
The major-third interval that establishes the chord's major base.
E
Perfect fifth (5)
Adds strength and stability.
G
Minor seventh (♭7)
Adds the defining minor-seventh color.