#1
What is the formula for a a regular 7 diminished triad, and a half diminished triad?
~Long live the 6-string~
#3
Fully diminished and half-diminished chords are not triads. They are 4 note chords.

Dimnished Triad-1 b3 b5
Fully Diminished Chord-1 b3 b5 bb7 (the bb7 is a double-flat 7, enharmonic to 6)
Half Diminished-1 b3 b5 b7

With C as the root, the chords are:
Triad-C Eb Gb
Full-C Eb Gb Bbb
Half-C Eb Gb Bb

Edit: Bbbb, WTF?
Last edited by bangoodcharlote at Jul 21, 2006,
#4
Well first off saying " a diminised 7 triad" is kinda funny, because a triad is 3 notes, and a 7th chord is 4 notes.
A triad will be some form of root, third, and fifth...in the case of diminished triad that will be :
1, b3, b5
And the fully diminshed 7th:
1, b3, b5, bb7
Finally the half diminised 7th( otherwise known as minor7(b5):
1, b3, b5, b7

Thats the short answer to your question. I would recommend really mastering triads first before moving on to 7th chords, as they all contain at least one triad.
#6
bang, you are correct saying A, as the enharmonic spelling, but it would be a "B double flat" ( Bbb), not B triple flat. And calling it Bbb is most technically correct, because of its function in a Cdim7 setting.