In music, a ninth is a compound interval consisting of an octave plus a second. Like the second, the interval of a ninth is classified as a dissonance in common practice tonality. Since a ninth is an octave larger than a second, its sonority level is considered less dense.
Major ninth
A major ninth is a compound musical interval spanning 14 semitones, or an octave plus 2 semitones. For instance, the interval between C<sub>4</sub> and D<sub>5</sub> (in scientific pitch notation) is a major ninth.
:<score sound>
{
\override Score.TimeSignature
- 'stencil = ##f
\relative c' {
\time 4/4
\set Score.tempoHideNote = ##t \tempo 1 = 20
<c d'>1
}
}
</score>
If transposed into a single octave, it becomes a major second or minor seventh. The major ninth is somewhat dissonant in sound.
Transposition
Some common transposing instruments sound a major ninth lower than written.
These include the tenor saxophone, the bass clarinet, the baritone/euphonium when written in treble clef, and the trombone when written in treble clef (British brass band music).
When baritone/euphonium or trombone parts are written in bass clef or tenor clef they sound as written.
Minor ninth
A minor ninth (m9 or -9) is a compound musical interval spanning 13 semitones, or 1 semitone above an octave (thus it is enharmonically equivalent to an augmented octave). For instance, the interval between C<sub>4</sub> and D<sub>5</sub> (in scientific pitch notation) is a minor ninth.
:<score sound>
{
\override Score.TimeSignature
- 'stencil = ##f
\relative c' {
\time 4/4
\set Score.tempoHideNote = ##t \tempo 1 = 60
<c des'>1
}
}
</score>
If transposed into a single octave, it becomes a minor second or major seventh. The minor ninth is rather dissonant in sound, and in European classical music, often appears as a suspension.
The fourth movement (an intermezzo) of Robert Schumann's Faschingsschwank aus Wien is constructed to feature prominent notes of the melody a minor ninth above the accompaniment:
thumb|center|600x600px| Schumann, Faschingsschwank Intermezzo, bars 1–4
Béla Bartók wrote a study in minor ninths for piano. Several of Igor Stravinsky's works open with a striking gesture that includes the interval of a minor 9th, either as a chord, as in Les noces and Threni, or as an upward melodic leap, as a in Capriccio for Piano and Orchestra, Symphony in Three Movements, and Movements for Piano and Orchestra.
Augmented ninth
An augmented ninth is a compound musical interval spanning 15 semitones, or 3 semitones above an octave. For instance, the interval between C<sub>4</sub> and D<sub>5</sub> (in scientific pitch notation) is a major ninth.
:<score sound>
{
\override Score.TimeSignature
- 'stencil = ##f
\relative c' {
\time 4/4
\set Score.tempoHideNote = ##t \tempo 1 = 60
<c dis'>1
}
}
</score>
Enharmonically equivalent to a compound minor third, if transposed into a single octave, it becomes a minor third or major sixth.
See also
- Augmented octave
- Augmented unison