About the Ebdim chord
To play Eb diminished, use the first shape above. Place your index finger on the 2nd fret of the G string, your middle finger on the 2nd fret of the E string, and your ring finger on the 3rd fret of the C string. Leave the A string open. Strum all four strings and check that each one rings cleanly.
Root
Eb
Quality
Diminished
Notes
Eb · Gb · Bbb
How the Ebdim chord works
Eb
Root(1)
The home note. It gives the chord its name.
Gb
Minor third(♭3)
The defining minor interval above the root.
Bbb
Diminished fifth(♭5)
A lowered fifth that adds harmonic tension.