Ninth - 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). It is a type of extended minor seventh. 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. Béla Bartók wrote a study in minor 9ths for piano. The fourth 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. Alexander Scriabin's Piano Sonata No. 9, 'Black Mass' is based around the interval of a minor ninth, creating an uncomfortable and harsh sound.