Introduction
The universe of music theory can often feel like a vast and complex landscape packed with numerous interrelated concepts. One such concept that frequently sparks curiosity is the starting note of a major scale – why is it always on the tonic? This article explores the underlying reasons and provides an understanding rooted in the foundational principles of music theory.

Understanding the Tonic

In the realm of music, the term “tonic” refers to the first degree or note of a musical scale. In a major scale, the tonic is the most stable and harmonically significant note, playing a central role in establishing the tonality or key of a piece of music. This note sets the emotional and harmonic framework for the entire composition.

The Structure of Diatonic Scales

Diatonic scales are scales made up of seven different pitches or notes used in Western music. Each scale follows a specific pattern of whole steps (W) and half steps (H). For a major scale, the pattern is: W-W-H-W-W-W-H.

When we examine the structure, it becomes clear why the tonic is the starting point. The tonic is the foundation upon which the entire scale and subsequent harmonies are built. It is the note from which the other notes derive their meaning and stability. Without a tonic, the scale would lose its tonal center and the sense of a key structure would be lost.

Key Considerations

Harmony and Stability: The tonic provides a stable and harmonically significant foundation. It is the note around which all other chords and progressions revolve. In a tonal system, the tonic serves as the most stable and resolving chord, often represented by the Roman numeral I.

Hierarchy of Tones: In a major scale, the supertonic (second note), median (third note), and dominant (fifth note) are all important but subordinate to the tonic. Each of these notes adds color and complexity but ultimately returns to the tonic for resolution.

Roman Numerals in Chord Progressions: Roman numerals represent chords within a key. The tonic chord is always I, which is why it is the default starting point. Trying to start on the supertonic (II), median (III), dominant (V), or leading tone (VII) would disrupt this natural hierarchy and the established chord progression structure.

The Role of the Tonic in Composition

The choice to begin a scale on the tonic is not arbitrary but rooted in the principles of tonal harmony and composition. Composers utilize the tonic to create a sense of resolution and completeness in their music. Beginning on the tonic provides a sense of stability and can help guide the listener through the harmonic journey of the piece.

Improvization and Composition: In improvisation, musicians often return to the tonic for a sense of resolution and to recharge the harmonic center. This is why the tonic is the default and most stable point to start composing or improvising from.

Conclusion

In music theory, the starting note of a major scale on the tonic is a fundamental concept with deep roots in tonal harmony. It is not just a matter of definition but a key element in establishing the tonality, stability, and direction of a piece. Understanding why the tonic is the starting note can provide valuable insight into the structure and function of Western music.

Further Reading

To delve deeper into this topic, explore the following resources:

Understanding Diatonic Scales Hierarchical Tones in Tonal Harmony Basics of Music Composition and Chord Progressions

Key Terms and Their Meanings

Tonic: The first degree or note of a musical scale, the most stable and harmonically significant note.

Supertonic: The second note of a diatonic scale.

Median: The third note of a diatonic scale.

Dominate: The fifth note of a diatonic scale.

Leading Tone: The seventh note of a diatonic scale, often leading back to the tonic.