Chords refer to any combination of two or more notes. Usually a chord will have at least three notes, but especially with tritones, sometimes composers use only two notes. Understanding how to create a tritone chord that consists only of the interval of a tritone requires you to place two notes six half-steps apart. Reference a chromatic scale if you have trouble accurately counting half-steps. When counting half-steps, don't count the first note. For instance, C to D consists of an interval of two half-steps.
Modern composers often utilize tritone triads that have a tritone between the bottom and top note. The method of building a tritone triad uses the same technique as creating tritone intervals. Composers will start with a root bass note and then add a minor third and a tritone from the bass note to create a tritone triad between the bottom and top notes. For instance, a chord with a C, E-flat and G-flat qualifies as a diminished chord.
Composers will often use the augmented sixth chord in music, which consists of tritones hidden with the intervals of the chord. In augmented sixth chords the tritone occurs between the third and the sixth of the three types of augmented sixth chords: Italian, French and German. The difference between these three chords is the third note of the triad. In the Italian augmented sixth, there is a major third between the bass note and the third note, there is another tritone between the bass and the third note of the French augmented sixth and a perfect fifth between the bass and the third note of the German augmented sixth chord.
The dominant seventh chord, the half-diminished chord and the fully diminished seventh chord all contain tritones. Diminished fifths and tritones are the same interval. The half-diminished seventh chord contains a tritone between the root and fifth of the chord, while the diminished seventh chord contains two tritones, between the root and fifth and the third and seventh of the chord. The dominant seventh chord contains a tritone between the third and the seventh of the chord.