Table 1.

Dyads created by combining a low note with each of the 11 notes above it

Rank	F0 ratio	Name	Abbreviation	Consonance
1	1.498307	Perfect 5th	P5	Perfectly consonant
2	1.33484	Perfect 4th	P4
3	1.681793	Major 6th	M6	Imperfectly consonant
4	1.259921	Major 3rd	M3
5	1.587401	Minor 6th	m6
6	1.189207	Minor 3rd	m3
7	1.781797	Minor 7th	m7	Dissonant
8	1.414214	Tritone	Tri
9	1.887749	Major 7th	M7
10	1.122462	Major 2nd	M2
11	1.059463	Minor 2nd	m2

Combining a low note with each of the 11 notes above it creates a different dyad, named after the ratio (“interval”) of the two notes. Intervals can be categorized as “perfectly consonant,” “imperfectly consonant,” and “dissonant.” The hierarchical ranking of intervals contributes to a sense of musical “key.” Intervals are ranked here by consonance in accordance with Western music theory, and with the pleasantness ratings of the younger group.