EDIT!!
There seems to be quite a few comments stating that it is impossible to rank 12 intervals in an octave by most consonant to dissonant so let me elaborate.
If a chord progression is developed through tension and release, that tension and release is accounted for by a combination of intervals (a chord) that through each bar go from dissonant (tension) to consonance (rest). If we acknowledge that a chord could be considered to be multiple intervals at work simultaneously, how can we absolutely deny their individual degrees of consonance and dissonance within context of a chord progression? The denial is absolutely baffling to me. It is obvious that the interval of a perfect fifth is more consonant than the interval of a minor second, so evidently the intervals do have their individual degree of consonance/dissonance relative to the root. I will even assume that maybe some of you good folks are jumping in the gun in your answers as opposed to what im specifically asking which revolves around interval to interval relationship and not for example a chord progression. I am not asking how this method would be applicable to a progression, i am very specifically asking what intervals are most consonant to dissonant relative to the root (interval) in 12tet. Nothing more and nothing less.
I also saw a comment stating "what may sound consonant to one listener may be dissonant to another". I think it is undeniable that any listener on planet earth would find an octave more dissonant than a minor second. So evidently a consonance/dissonance ranking does exist and i will paste below my actual ranking which i think some confused my example one for a real ranking.
My question is, is the ranking below applicable to 12tet, not by its numerical values which i understand differ slightly, but the general sound.
I hope this helps.
- Unison = 1:1 Perfect Consonance (1st note of an octave)
- Octave = 2:1 Perfect Consonance (13th note of an octave)
- Perfect Fifth = 3:2 Perfect Consonance (8th note of an octave)
- Perfect Fourth = 4:3 Dissonant when the bass note (6th note of an octave)
- Major Sixth = 5:3 Imperfect Consonance (10th note of an octave)
- Major Third = 5:4 Imperfect Consonance (5th note of an octave)
- Minor Third = 6:5 Impefect Consonance (4th note of an octave)
- Minor Sixth = 8:5 Imperfect Consonance (9th note of an octave)
- Minor Seventh = 9:5 Dissonant (11th note of an octave)
- Major Second = 9:8 Dissonant (3rd note of an octave)
- Major Seventh = 15:8 Dissonant (12th note of an octave)
- Minor Second = 16:15 Dissonant (2nd note of an octave)
- Tritone = 7:5 Dissonant (7th note of an octave)