The tritone is a musical phenomenon steeped in both mystery and scientific precision. As a specific kind of musical interval, the tritone has etched its mark onto the grand tapestry of music theory and practice.
To better understand what a tritone is, one must delve into the realm of music theory. A tritone is an interval composed of three whole tones, which amounts to six semitones. When two pitches are three whole tones apart, they form a tritone. This unique blend of tones and semitones gives the tritone its distinctive auditory quality, a sound that stands apart from other musical intervals.
However, the tritone is not a common occurrence. When observing a diatonic scale, which comprises seven distinct pitches, one encounters the tritone only once. This tritone forms between the fourth and seventh degrees of the scale. For example, the tritone appears in the interval between F and B in the context of a C major scale. In a G major scale, the tritone exists between C and F sharp.
However, this systematic recognition of the tritone comes from a relatively modern understanding of music and musical instruments. In the annals of musical history, particularly before the invention of keyboard instruments, there was no standard or ‘universal tuning.’ Instruments were tuned in an array of unique ways, each contributing to the rich variety of sounds and pitches that defined the music of the time.
In the grand evolution of modern harmony, the tritone stands as a seminal influence. Its presence necessitated changes and innovations that would forever alter the music landscape. Before the development of uniform tuning standards and the subsequent creation of keyboard instruments, accidentals (notes altered by a half-step from their original pitch) were not universally recognized or used. Each instrument, with its unique tuning, followed its own pitches and tonal adjustments system.
The emergence of the tritone, with its unique and somewhat discordant sound, challenged this status quo. The peculiar sound of the tritone was dissonant and difficult to incorporate into the music of the time. Thus, the first accidentals, F sharp and B flat, were developed. These accidentals were conceptualized and introduced to ‘solve’ the problem posed by the tritone. Using F sharp and B flat made it possible to include the tritone in musical compositions without causing discordance.
Before the widespread adoption of keys in music theory, the system of modes reigned supreme. These modes, which used only the keyboard’s white keys, formed different scales and represented unique patterns of tones and semitones. The only way to alter the pattern of tones and semitones in a mode was to start on a different note.
Each mode carried its own distinctive flavor and character. Modes like Ionian and Lydian were known for producing joyful, uplifting music. Others, such as Dorian and Phrygian, lent themselves more to somber, mournful themes. This classification of modes formed the basis of much of the music composed during this period.
However, one note in the scale posed a unique problem: B. In the context of the B scale or the Locrian mode, the fifth degree of the scale was not a perfect fifth. Instead, it was an augmented fourth, which was a tritone.
The presence of a tritone within the Locrian mode disrupted the conventional understanding of music and harmony. This unprecedented development led to the tritone being dubbed diabolus in music, or ‘The Devil in music.’ This naming underlines the sense of shock and unease that the tritone’s unique dissonance sparked in listeners and composers alike.
The Locrian mode, with its inherent tritone, was rarely utilized in musical compositions of the time. However, the tritone was not to be silenced. Composers keen on leveraging this mode’s unique sound and character began experimenting with the notorious B to F interval. Some composers lowered the pitch of the B until it formed a perfect fifth below F, while others raised the F until it sat a perfect fifth above B. These modifications resulted in the creation of B flat and F sharp, the first musical accidentals.
These revolutionary alterations to the musical landscape marked a paradigm shift in the realm of music theory and practice. They paved the way for new musical possibilities and interpretations, ushering in the next era of music. The tritone, once a symbol of discordance and disruption, became a catalyst for innovation and growth within the field of music.
The tritone’s distinctive sound has intrigued and baffled musicologists for centuries. Its dissonance, which is immediately noticeable and often somewhat unsettling, stands out starkly against more conventionally harmonious intervals. There is a scientific explanation for why the tritone often sounds jarring or unpleasant to the human ear. The human brain is innately inclined to seek harmony and symmetry in music. When we encounter a dissonant sound like the tritone, it elicits a slightly unsettling emotional reaction because it’s unexpected and differs from what our brains perceive as harmonious.
This sense of discordance ties back to the concept of pitch and how frequencies relate to each other. When two pitches have a simple ratio, they tend to sound harmonious together. For example, the ratio of two notes an octave apart is a pleasing 2:1. They are so consonant that we often refer to both notes by the same name. The next most harmonious interval is the perfect fifth, with a ratio of 3:2.
However, the tritone defies this trend. Depending on the tuning, its notes end up in a rather unsightly proportion of either 45:32 or 64:45. This irregular ratio is quite discordant to the human ear. Still, the tritone has found a unique niche for itself – it has become a mainstay in alarms and emergency sirens due to its distinctive sound!
Rumors have long circulated that music containing the tritone was banned in churches because of its purported association with the devil. However, as tantalizing as these stories might be, no concrete evidence supports this claim. It is more plausible that the strict harmony rules followed by composers during that time prohibited using the augmented fourth (the tritone) for musical reasons, not due to any association with diabolical elements.
Despite its notorious past, the tritone is now widely recognized in popular songs and catchy theme tunes, thanks to its unique and immediately recognizable sound. Two well-known examples of the tritone in music include “Maria” from Leonard Bernstein’s ‘West Side Story’ and Jimi Hendrix’s “Purple Haze“.
These examples show how the tritone, once shunned for its dissonance, has found acceptance and even prominence in modern music. The tritone’s distinct sound now serves as a powerful tool for creating memorable hooks and melodies that captivate listeners.
The tritone’s journey from musical outcast to celebrated interval is a testament to the power of innovation and the endless possibilities of music. Today, it’s clear that the tritone, despite its dissonance and unusual sound, holds a unique place in the rich tapestry of music, resonating with its distinctive charm in compositions worldwide.