Unlocking the Augmented Second: The Exotic Interval of Music Theory

Summary:

This article delves into the augmented second, a unique and colorful interval in music theory. We will explore its definition, its characteristic sound spanning three semitones, and its crucial role in forming the harmonic minor scale. Understanding the augmented second is key to appreciating the dramatic tension and exotic flair it brings to various musical styles, from classical masterpieces to vibrant world music.

Keywords:

Augmented Second, Music Theory, Intervals, Harmonic Minor Scale, Dissonance, Semitones, Music Education, Exotic Scales, Enharmonic Equivalent, Melodic Interval, MusicXML

Introduction:

In the vast world of music, intervals are the fundamental building blocks of melody and harmony. We're all familiar with the simple, stepwise motion of major and minor seconds. But what happens when we stretch that step just a little bit further? We enter the fascinating territory of the augmented second. While spelled as a 'second' (e.g., from a C to a D), its sound is wide, tense, and surprisingly dramatic. This interval is a potent musical spice, adding a distinct and often "exotic" flavor that can transport the listener from a classical concert hall to a bustling bazaar in a single leap.

Definition and Classification:

An augmented second is an interval that is one chromatic semitone wider than a major second. Since a major second spans two semitones (like C to D), an augmented second spans three semitones (like C to D-sharp). The defining feature is its spelling: the letter names must be adjacent in the musical alphabet (C-D, F-G, A-B, etc.).

You might notice that C to D-sharp sounds identical to C to E-flat. This is called an enharmonic equivalence; the augmented second sounds the same as a minor third. So, why the different name? The answer lies in musical context and function. The spelling reveals its role in a scale or chord. It is classified as a dissonant interval due to the tense melodic leap and the harmonic friction it creates. This tension, however, is precisely what makes it so expressive.

Hearing the Augmented Second: Notation and Sound

Example 1: Harmonic Augmented Seconds

The following examples show the augmented second played as a harmonic interval (both notes sounding at once). Notice the dissonant, tense quality. Each pair of notes has adjacent letter names but spans three semitones.

Practical Applications:

The augmented second is not just a theoretical concept; it's a powerful expressive tool. Its most common home is the harmonic minor scale, where it occurs between the lowered 6th degree (the submediant) and the raised 7th degree (the leading tone). This interval gives the scale its signature sound and creates a strong pull towards the tonic. You can hear this effect in countless classical, jazz, and metal pieces.

Beyond the harmonic minor, the augmented second is a defining feature of various folk or "exotic" scales, such as the Hungarian Minor and Byzantine (Phrygian Dominant) scales. This makes it a prominent feature in Klezmer, Flamenco, and Middle Eastern musical traditions. For a famous classical example, listen to the B-section of Mozart's "Rondo alla Turca," where the melody and harmony use this interval to evoke the sound of a Turkish military band, a popular trope at the time.

Historical Figures:

Composers have long been captivated by the augmented second's unique color. During the Romantic era, composers seeking to express nationalism or exoticism used it frequently. Nikolai Rimsky-Korsakov, a master of orchestration, filled his work Scheherazade with melodies built around scales featuring the augmented second to paint a vivid picture of the Arabian Nights. Similarly, Franz Liszt incorporated the interval into his Hungarian Rhapsodies to capture the spirit of Romani ("Gypsy") folk music. But its use goes back much further. J.S. Bach masterfully employed the harmonic minor scale, with its characteristic augmented second, to create moments of profound pathos and drama. He often used it as a form of "word painting" to aurally represent sorrow or suffering in his sacred cantatas and passions, proving the interval's timeless expressive power.

Fun Facts:

• In early vocal music, the wide, awkward leap of a melodic augmented second was often considered difficult to sing and was sometimes referred to as a "forbidden interval" by theorists who preferred smoother melodic lines.
• The Hungarian Minor Scale is sometimes called the "Double Harmonic Scale" because it contains not one, but two augmented seconds, giving it an even more intensely exotic flavor.
• The enharmonic twin of the augmented second, the minor third, is more common than you think! The classic "ding-dong" of many doorbells is a minor third, proving this dramatic sound is woven into our daily lives.
• In jazz improvisation, the augmented second is a key feature of the "Altered Scale" (the 7th mode of the melodic minor), where improvisers use it to create sophisticated tension over dominant seventh chords.

Conclusions:

The augmented second is far more than a music theory oddity. It is a potent interval that injects tension, drama, and vibrant color into music. Defined by its three-semitone span between adjacent letter names, it is the heart of the harmonic minor scale and a gateway to musical styles from around the world. From the drama of a Bach fugue to the fire of Flamenco, the augmented second is a testament to how a single interval can define a sound. By learning to recognize it by ear and by sight, you unlock a new layer of musical expression. Now that you're familiar with its unique character, where will you hear the augmented second next?

References:

1. Piston, W. & DeVoto, M. (1987). Harmony (5th ed.). W. W. Norton & Company.

2. Laitz, S. G. (2015). The Complete Musician: An Integrated Approach to Theory, Analysis, and Listening. Oxford University Press.

3. Tymoczko, D. (2011). A Geometry of Music: Harmony and Counterpoint in the Extended Common Practice. Oxford University Press.