music Music is generally defined as the art of arranging sound to create some combination of form, harmony, melody, rhythm or otherwise expressive content. Exact definitions of music vary considerably around the world, though it is an aspect ...

, a ninth is a

compound Compound may refer to: Architecture and built environments * Compound (enclosure), a cluster of buildings having a shared purpose, usually inside a fence or wall ** Compound (fortification), a version of the above fortified with defensive struct ...

interval consisting of an

octave In music, an octave ( la, octavus: eighth) or perfect octave (sometimes called the diapason) is the interval between one musical pitch and another with double its frequency. The octave relationship is a natural phenomenon that has been refer ...

plus a

second The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds ...

. Like the second, the interval of a ninth is classified as a dissonance in

common practice In European art music, the common-practice period is the era of the tonal system. Most of its features persisted from the mid-Baroque period through the Classical and Romantic periods, roughly from 1650 to 1900. There was much stylistic evolutio ...

tonality Tonality is the arrangement of pitches and/or chords of a musical work in a hierarchy of perceived relations, stabilities, attractions and directionality. In this hierarchy, the single pitch or triadic chord with the greatest stability is call ...

. 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

semitone A semitone, also called a half step or a half tone, is the smallest musical interval commonly used in Western tonal music, and it is considered the most dissonant when sounded harmonically. It is defined as the interval between two adjacent no ...

s, or an octave plus 2 semitones. 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 instrument A transposing instrument is a musical instrument for which music notation is not written at concert pitch (concert pitch is the pitch on a non-transposing instrument such as the piano). For example, playing a written middle C on a transposing i ...

s sound a major ninth lower than written. These include the

tenor saxophone The tenor saxophone is a medium-sized member of the saxophone family, a group of instruments invented by Adolphe Sax in the 1840s. The tenor and the alto are the two most commonly used saxophones. The tenor is pitched in the key of B (while th ...

, the

bass clarinet The bass clarinet is a musical instrument of the clarinet family. Like the more common soprano B clarinet, it is usually pitched in B (meaning it is a transposing instrument on which a written C sounds as B), but it plays notes an octave bel ...

, the

baritone A baritone is a type of classical male singing voice whose vocal range lies between the bass and the tenor voice-types. The term originates from the Greek (), meaning "heavy sounding". Composers typically write music for this voice in the r ...

euphonium The euphonium is a medium-sized, 3 or 4-valve, often compensating, conical-bore, tenor-voiced brass instrument that derives its name from the Ancient Greek word ''euphōnos'', meaning "well-sounding" or "sweet-voiced" ( ''eu'' means "well" ...

when written in

treble clef A clef (from French: 'key') is a Musical notation, musical symbol used to indicate which Musical note, notes are represented by the lines and spaces on a musical staff (music), stave. Placing a clef on a stave assigns a particular pitch to ...

, and the

trombone The trombone (german: Posaune, Italian, French: ''trombone'') is a musical instrument in the Brass instrument, brass family. As with all brass instruments, sound is produced when the player's vibrating lips cause the Standing wave, air column ...

when written in treble clef (

British brass band In Britain, a brass band (known regionally as a silver band or colliery band) is a musical ensemble comprising a standardized range of brass and percussion instruments. The modern form of the brass band in the United Kingdom dates back to the 1 ...

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). 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 (music), suspension. Béla Bartók wrote a study in minor 9ths for piano. The fourt
movement
(an intermezzo) of Robert Schumann's ''Faschingsschwank aus Wien'', is a constructed to feature prominent notes of the melody a minor ninth above the accompaniment: Fassingschwank Intermezzo, bars 1-4

Alexander Scriabin's Piano Sonata No. 9 (Scriabin), Piano Sonata No. 9, 'Black Mass' is based around the interval of a minor ninth, creating an uncomfortable and harsh sound. Several of Igor Stravinsky's works open with a striking gesture that includes the interval of a minor 9th, either as a chord: ''Les Noces'
(1923)
and ''Threni (Stravinsky), Threni'
(1958)
or as an upward melodic leap: ''Capriccio for Piano and Orchestra'
(1929)
''Symphony in Three Movements'
(1946)
and ''Movements for Piano and Orchestra'
(1960)

Augmented ninth

An augmented ninth is a compound musical interval spanning 15 semitones, or 3 semitones above an octave. Enharmonically equivalent to a compound minor third, if transposed into a single octave, it becomes a minor third or major sixth. See: Dominant seventh sharp ninth chord.

Ninth chords

Three types of ninth chords may be distinguished: dominant (9), major (M9), and minor (m9).Bruce Buckingham, Eric Paschal (2001). ''Rhythm Guitar: The Complete Guide'', p.58. . They may easily be remembered as the chord quality of the seventh does not change with the addition of the second scale degree, which is a major second in both major and minor, thus: 0 4 7 t + 2 = dominant seventh chord, dominant seventh + ninth = dominant ninth chord 0 4 7 e + 2 = major seventh chord, major seventh + ninth = major ninth chord 0 3 7 t + 2 = minor seventh chord, minor seventh + ninth = minor ninth chord The dominant ninth (V₉) is a dominant seventh plus a major or minor ninth.Helen S. Leavitt (1916). ''Practical Lesson Plans in Harmony'', p.32. Ginn and Company. "In major keys the dominant ninth is usually major, though occasionally it is chromatically altered to a minor. In minor keys a similar chromatic change from minor to major takes places."

References