Superfourth

A superfourth is an interval too wide to sound like a perfect fourth and too narrow to sound like a tritone. Margo Schulter, in her article Regions of the Interval Spectrum, proposes an approximate range for a superfourth to be from 528 ¢ to 560 ¢. Some of the simplest superfourths in just intonation are 11/8 (about 551.3 ¢) and 15/11 (about 537 ¢), both undecimal (11-based) superfourths; and 48/35 (about 546.8 ¢) and 49/36 (about 533.7 ¢), both septimal (7-based) superfourths.

The inversion of a superfourth is a subfifth.

Of course, this categorization should not be taken for granted. Since music is subjective and culturally influenced, the borders of what is a superfourth are "fuzzy". Other descriptions are possible and legitimate.

Examples

Below is a list of some intervals in the superfourth range, both just and tempered.

Interval	Cents	Prime limit (if applicable)
6\88cET or 11\25	528.000	-
19/14	528.687	19
87/64	531.532	29
34/25	532.328	17
4\9	533.333	-
49/36	533.742	7
64/47	534.493	47
15/11	536.951	11
13\29	537.931	-
56/41	539.764	41
9\20	540.000	-
41/30	540.794	41
175/128	541.453	7
14\31	541.935	-
26/19	543.015	19
5\11	545.455	-
37/27	545.479	37
48/35	546.815	7
11\24	550.000	-
11/8	551.318	11
6\13	553.846	-
62/45	554.812	31
40/29	556.737	29
13\28	557.143	-
243/176	558.457	11
29/21	558.796	29
47/34	560.551	47
7\15	560.000	-

See also

• 43/31 – a tritone with a "superfourth-ish" taste
• Interval category
• Gallery of just intervals
• Subfifth – the octave complement region