Western classical music Classical music generally refers to the art music of the Western world, considered to be #Relationship to other music traditions, distinct from Western folk music or popular music traditions. It is sometimes distinguished as Western classical mu ...

, an augmented second is an interval created by widening a

major second In Western music theory, a major second (sometimes also called whole tone or a whole step) is a second spanning two semitones (). A second is a musical interval encompassing two adjacent staff positions (see Interval number for more de ...

by a chromatic semitone, spanning three semitones and enharmonically equivalent to a

minor third In music theory, a minor third is a interval (music), musical interval that encompasses three half steps, or semitones. Staff notation represents the minor third as encompassing three staff positions (see: interval (music)#Number, interval numb ...

12-tone equal temperament 12 equal temperament (12-ET) is the musical system that divides the octave into 12 parts, all of which are Equal temperament, equally tempered (equally spaced) on a logarithmic scale, with a ratio equal to the Twelfth root of two, 12th root of 2 ...

.Benward & Saker (2003). ''Music: In Theory and Practice, Vol. I'', p.54. . Specific example of an A2 not given but general example of major intervals described. For instance, the interval from C to D is a major second, two semitones wide, and the interval from C to D is an augmented second, spanning three semitones.

Usage

Augmented seconds occur in many scales, including the various modes of the harmonic minor and double harmonic scales. In harmonic minor, the augmented second occurs between the sixth and seventh scale degrees. For example, in the scale of A harmonic minor, the notes F and G form the interval of an augmented second. This distinguishing feature of harmonic minor scales occurs as a consequence of the seventh scale degree having been chromatically raised in order to allow

chords Chord or chords may refer to: Art and music * Chord (music), an aggregate of musical pitches sounded simultaneously ** Guitar chord, a chord played on a guitar, which has a particular tuning * The Chords (British band), 1970s British mod ...

in a minor key to follow the same rules of

cadence In Classical music, Western musical theory, a cadence () is the end of a Phrase (music), phrase in which the melody or harmony creates a sense of full or partial resolution (music), resolution, especially in music of the 16th century onwards.Don ...

observed in major keys, where the V chord is "dominant" (that is, contains a major triad plus a

minor seventh In music theory, a minor seventh is one of two musical intervals that span seven staff positions. It is ''minor'' because it is the smaller of the two sevenths, spanning ten semitones. The major seventh spans eleven. For example, the interval ...

). An augmented second also appears in the

diminished seventh chord The diminished seventh chord is a four-note chord (a seventh chord) composed of a Root (chord), root note, together with a minor third, a diminished fifth, and a diminished seventh above the root: (1, 3, 5, 7). For example, the dim ...

(in

1st First most commonly refers to: * First, the ordinal form of the number 1 First or 1st may also refer to: Acronyms * Faint Images of the Radio Sky at Twenty-Centimeters, an astronomical survey carried out by the Very Large Array * Far Infrared a ...

2nd A second is the base unit of time in the International System of Units (SI). Second, Seconds, The Second, or (The) 2nd may also refer to: Mathematics * 2 (number), as an ordinal (also written as ''2nd'' or ''2d'') * Minute and second of arc, ...

, and 3rd inversion) between the diminished seventh and the root, and in the German sixth chord between the and degrees.

Tuning

An augmented second is enharmonically equivalent to a

(), but is distinguished in other tunings. In tunings near

quarter-comma meantone Quarter-comma meantone, or -comma meantone, was the most common meantone temperament in the sixteenth and seventeenth centuries, and was sometimes used later. In this system the perfect fifth is flattened by one quarter of a syntonic comma with ...

it approximates the

septimal minor third Septimal may refer to: *Septimal chromatic semitone, the interval 21:20, about 84.47 cents *Septimal comma, a small musical interval in just intonation divisible by 7 *Septimal diatonic semitone, the interval 15:14, about 119.44 cents *S ...

of ratio 7:6 (). In

pythagorean tuning Pythagorean tuning is a system of musical tuning in which the frequency ratios of all intervals are determined by choosing a sequence of fifthsBruce Benward and Marilyn Nadine Saker (2003). ''Music: In Theory and Practice'', seventh editi ...

and schismatic temperament, however, it closely approximates the classical minor third of ratio 6:5 (). In superpyth temperament, the fifth is sharpened so that the augmented second reaches the classical major third of ratio 5:4 (). The 75:64 just augmented second () arises in the justly tuned C

harmonic minor scale The harmonic minor scale (or Aeolian ♮7 scale) is a Scale (music), musical scale derived from the natural minor scale, with the minor seventh degree raised by one semitone to a major seventh, creating an augmented second between the sixth and ...

between A (tuned to 8:5) and B (tuned to 15:8).Paul, Oscar (1885).
A manual of harmony for use in music-schools and seminaries and for self-instruction
', p.165. Theodore Baker, trans. G. Schirmer. It is very close to the 7:6 septimal minor third, differing by a septimal kleisma.

References

{{DEFAULTSORT:Augmented Second Augmented intervals Seconds (music)