About the Bmaj7 chord
To play B major 7th, use the first shape above. Use your index finger to barre the 2nd fret across the E and A strings. Place your ring finger on the 3rd fret of the G string and your pinky finger on the 3rd fret of the C string. Strum all four strings and check that each one rings cleanly.
Root
B
Quality
Major 7th
Notes
B · D# · F# · A#
How the Bmaj7 chord works
B
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.
A#
Major seventh(7)
Adds a major seventh above the root.