Viennese trichord

In music theory, a Viennese trichord (also known as Viennese fourth chord and tritone-fourth chord^[2]), named for the Second Viennese School, is a pitch set with prime form (0,1,6). Its Forte number is 3-5. The sets C–D♭–G♭ and C–F♯–G are both examples of Viennese trichords, though they may be voiced in many ways.

Viennese trichord as a part of 6-z17, embellishing the first chord, from Bill Evans's opening to "What Is This Thing Called Love?"^[3]

Viennese trichord

Component intervals from root
tritone
minor second
root
Tuning
8:12:17[1]
Forte no. / Complement
3-5 / 9-5
Interval vector
<1,0,0,0,1,1>

Viennese trichord

Viennese trichord as dominant

Quartal Viennese trichord.^[2]

According to Henry Martin, "[c]omposers such as Webern ... are partial to 016 trichords, given their 'more dissonant' inclusion of ics 1 and 6."^[4]

In jazz and popular music, the chord formed by the inversion of the set usually has a dominant function, being the third, seventh, and added fourth/eleventh of a dominant chord with elided root^[3] (and fifth, see jazz chord). For example, the Viennese trichord of C-F#-G could be considered a D11/C: D (elided) - F# - A (elided) - C - G.

3-5

Prime	Inverse
0,1,6	0,6,e
1,2,7	1,7,0
2,3,8	2,8,1
3,4,9	3,9,2
4,5,t	4,t,3
5,6,e	5,e,4
6,7,0	6,0,5
7,8,1	7,1,6
8,9,2	8,2,7
9,t,3	9,3,8
t,e,4	t,4,9
e,0,5	e,5,t