Consonance and dissonance
In music, consonance and dissonance are words which are used to describe certain musical intervals or chords. The adjectives are consonant and dissonant.
A consonant interval or chord is one which sounds stable and pleasant. It could, for example, be the end of a piece of music. For example: C and E sound well together, or the chord C, E and G (a C major chord).
A dissonant interval or chord is one which sounds unstable. It may even sound harsh by itself. The notes seem to clash. It cannot be the end of the piece of music (if the music is a normal, traditional tonal piece). It sounds as if it wants to move on to a consonant interval (this is called "resolving" onto a consonant chord). The notes C and Fsharp together make a dissonant interval. The chord C - Dsharp - Fsharp is a dissonant interval: it is full of tension, and it sounds as if it wants to "resolve" onto C - E - G.
Scientifically a consonant interval is one in which the two notes vibrate at frequencies which have a simple mathematical relationship, e.g. in two notes which are an octave apart the higher note vibrates exactly twice as fast. If they are a fifth apart the top note vibrates 1 1/2 times as fast as the lower note. The more complicated mathematically the interval, the more dissonant it will sound.
Consonance And Dissonance Media
- Perfect octave on C = C'. * * Just: 2:1 = 1200 cents. * Equal-tempered: 212/12:1 = 1200 cents. * Limit: 3-limit. * MIDI pitch bend: none*MIDI.
- Minor second on C = D♭. * * Equal-tempered: 21/12:1 = 100 cents. * MIDI pitch bend: 0,64
Animation of Dynamic Tonality's mapping of partials to notes in accordance with the syntonic temperament.
- Just perfect fifth on C = G. 3:2 = 701.96 cents.* * Limit: 3-limit. * MIDI pitch bend: 80,64* MIDI file.
- Major tone on C = D. 9:8 = 203.91 cents.* * Limit: 3-limit. * MIDI pitch bend: 32,65
- Major semitone/Minor diatonic semitone on C = C17♯ (Ben Johnston's notation). 17/16 = 104.96 cents.* * Limit: 17-limit.*17th harmonic.
Dominant seventh tritone resolution
ii-V-I turnaround in C.
Machaut "Je ne cuit pas qu'onques"
Bach Preludio XXI from Well-tempered Clavier, Vol 1
Bach St Matthew Passion closing bars
Bach BWV 54 opening
Haydn Symphony 82 1st movement bars 51–63
Dissonance in Mozart's Adagio and Fugue in C minor, K. 546
Mozart Dissonance Quartet opening bars
Mozart, from Piano Concerto No. 21, 2nd movement bars 12–17
Beethoven Symphony No. 9, finale opening bars
Beethoven Symphony No. 9, finale bars 208ff
Mahler Symphony No. 10 Adagio bars 201–213
