Diminished unison

diminished unison

Inverse	augmented octave
Name
Other names	augmented unison (depending on context)
Abbreviation	dim1
Size
Semitones	-1
Interval class	1
Just interval	15:16; 24:25 (and others)
Cents
Equal temperament	-100
24 equal temperament	-100
Just intonation	-112; -71 (and others)

Augmented octave and diminished unison.^[1][2][3][4] Note how the diminished unison is essentially equivalent to the augmented unison.  Play (help·info) ( simultaneously (help·info))

"Diminished unison" is a non-standard and widely unaccepted term for the musical interval known as the augmented unison. The diminished unison would theoretically be one semitone smaller than a unison, for example, from C to C♭. Many music theorists do not consider the diminished unison as a legitimate interval^{[5][6][7][8][9][10][11][12]} because the interval is made larger rather than smaller, so it might perhaps be better called an augmented unison: C to C♭ is the same as C♭ to C.^[6]

Brian Blood^[13] explains it this way:

The interval from C to C flat is called the diminished unison or the diminished prime[.]

Some theorists do not allow the diminished unison because the C flat lies below the C natural and this breaks the[ir] rule that all dyadic intervals are named from the lower note.

The diminished unison is, in theory, the inversion of the augmented octave (although most theorists still simply call this interval the augmented unison). Note, though, that the inverted notes do not cross over: for example, C-C♯ (an augmented octave higher) inverts to C-C♯ (a diminished unison higher). In this case the C♯ is still above the C. This is unlike all other inversions in which the lower note becomes the higher note and vice versa: for example, C-F (a perfect fourth higher) inverts to C-F (a perfect fifth lower). This is why one theorist has stated that, "the flattened unison is an augmented unison, and the sharpened unison is a diminished unison".^[1]

See also

• Minor ninth

Sources

1. ^ ^{a b} Sembos (2006). Principles of Music Theory, p.51. ISBN 1430309555. online.
2. ^ Porter, Steven (1986). Music, A Comprehensive Introduction, p.66. ISBN 9780935016819.
3. ^ Burrows, Terry (1999). How To Read Music, p.62. ISBN 9780312241599.
4. ^ Middleton, Robert (1967). Harmony in Modern Counterpoint, p.20. Allyn and Bacon.
5. ^ Kostka and Payne (2003). Tonal Harmony, p.21. ISBN 0072852607. "There is no such thing as a diminished unison."
6. ^ ^{a b} Day and Pilhofer (2007). Music Theory for Dummies, p.113. ISBN 0764578383. "There is no such thing as a diminished unison, because no matter how you change the unisons with accidentals, you are adding half steps to the total interval."
7. ^ Surmani, Andrew; Karen Farnum Surmani, Morton Manus (2009). Alfred's Essentials of Music Theory: A Complete Self-Study Course for All Musicians. p. 135: Alfred Music Publishing. pp. 153. ISBN 0739036351. "Since lowering either note of a perfect unison would actually increase its size, the perfect unison cannot be diminished, only augmented.". 
8. ^ (1908). The Journal of School Music, p.263. "What he [Prof. White in Harmony and Ear Training] calls the 'diminished prime or unison' cannot possibly occur. It is simply an augmented unison. Because unison is 'the relation of two tones at the same pitch,' and when one of these is chromatically distanced, it creates the contradiction in terms known as 'augmented' unison; but the other term, 'diminished unison' is impossible on the face of it, because the 'same pitch' cannot be made less."
9. ^ Gardner, Carl Edward (1912). Essentials of Music Theory, p.38. C. Fischer. ISBN 9781440067808. "The prime is also called an unison, but in speaking of intervals, it should always be called a prime. Correctly speaking, a perfect prime is not an interval, but in the theory of music it is so called. There is good reason for making this error, but none for called a diminished prime a diminished unison."
10. ^ Smith, Uselma Clarke (1916). Keyboard Harmony, p.15. The Boston Music Company. "Note that the diminished unison and octave are not commonly used."
11. ^ Aikin, Jim (2004). A Player's Guide to Chords & Harmony, p.32. ISBN 9780879307981. "In case you were wondering, there's no such thing as a diminished unison."
12. ^ Arthur Foote, Walter Raymond Spalding (1905). Modern Harmony in its Theory and Practice, p.5. Arthur P. Schmidt. "a diminished unison is unthinkable, and the diminished 2d and 9th are of no practical use:..."
13. ^ Blood, Brian (2008 rev 2009). "Intervals". Music theory online. Dolmetsch Musical Instruments. http://www.dolmetsch.com/musictheory12.htm#unisons. Retrieved 25 December 2009.