About the Bb7 chord
To play Bb dominant 7th, use the first shape above. Use your index finger to barre the 1st fret across the G, C, E, and A strings. Place your middle finger on the 2nd fret of the C string. Strum all four strings and check that each one rings cleanly.
Root
Bb
Quality
Dominant 7th
Notes
Bb · D · F · Ab
How the Bb7 chord works
Bb
Root(1)
The home note. It gives the chord its name.
D
Major third(3)
The major-third interval that establishes the chord's major base.
F
Perfect fifth(5)
Adds strength and stability.
Ab
Minor seventh(♭7)
Adds the defining minor-seventh color.