Guitar chords in the key of D major:
Chord Ddim7 notes: D, Ab, B and F. You must leave out the 6th and 5th strings.
The guitar strings 4(D) and 2(B) are left open.
Ddim7 - D diminished seventh guitar chord's alternative names: D°, D°7, Do7, D7dim. See also: Ddim and Dm7b5.
Steps: 1-b3-b5-6(or bb7).
1(D), b3(F), b5(G#/Ab), 6(B).