Major and minor
In music theory, major and minor designate two primary categories of scales, keys, chords, and modes that underpin the tonal system of Western music, distinguished primarily by the quality of the third scale degree relative to the tonic. A major scale or key features a major third interval from the tonic to the mediant, yielding a bright, stable, and consonant sound often associated with happiness or resolution. In contrast, a minor scale or key employs a minor third, producing a darker, more introspective, or tense tonality frequently linked to melancholy or urgency.[1] The major scale, also known as the Ionian mode, is constructed using a specific sequence of intervals: whole step, whole step, half step, whole step, whole step, whole step, half step (W-W-H-W-W-W-H). This pattern defines the 12 major keys, each corresponding to a different tonic note, with key signatures ranging from no sharps or flats (C major) to seven sharps (C-sharp major) or seven flats (C-flat major). Key signatures for major keys follow a predictable order, with sharps added in the sequence F, C, G, D, A, E, B, and flats in the reverse order B, E, A, D, G, C, F, facilitating the identification of the tonic as the note a half step above the last sharp or the second-to-last flat.[1][2] Minor keys, rooted in the Aeolian mode or natural minor scale, follow the interval pattern whole step, half step, whole step, whole step, half step, whole step, whole step (W-H-W-W-H-W-W), which lowers the third, sixth, and seventh degrees compared to the parallel major key sharing the same tonic. Unlike the uniform major scale, minor scales vary in form: the natural minor uses the basic pattern; the harmonic minor raises the seventh degree by a half step to create a stronger leading tone for resolution; and the melodic minor ascends with raised sixth and seventh degrees while often descending as natural minor, adapting to melodic context in compositions.[3] Minor key signatures mirror those of their relative major keys—located a minor third above the tonic—and include three additional flats relative to the parallel major, resulting in 12 minor keys with signatures from no sharps or flats (A minor) to equivalents of seven sharps or flats.[3] A crucial relationship exists between major and minor keys: each major key has a relative minor sharing the same key signature but starting on the sixth degree of the major scale (a minor third below the major tonic), and vice versa, allowing composers to modulate seamlessly between them without altering accidentals. Parallel major and minor keys, by contrast, share the same tonic but differ in signature by three flats (or sharps when transposed). These distinctions extend to chords, where major triads include a major third and perfect fifth above the root for a stable sound, while minor triads feature a minor third for a subdued quality, influencing harmony, melody, and overall emotional expression in genres from classical to contemporary music.[3]Core Elements
Intervals
In music theory, an interval is defined as the distance between two pitches, either sounded simultaneously (harmonic interval) or sequentially (melodic interval), typically measured in semitones (half steps) or whole tones (two semitones).[4][5] These measurements form the foundational building blocks for distinguishing major and minor qualities in Western music, as the specific size of an interval determines its character and role in larger structures.[6] Intervals are classified into two primary categories based on their consonant qualities and historical perceptions of stability. Perfect intervals—unison (0 semitones), perfect fourth (5 semitones), perfect fifth (7 semitones), and octave (12 semitones)—are considered inherently consonant and unaltered by major or minor designations, reflecting their symmetric and stable nature in tuning systems.[4] In contrast, imperfect intervals such as seconds, thirds, sixths, and sevenths are qualified as major or minor, where the major variant is larger by one semitone and often perceived as brighter or more open.[5] Interval ratios originated in Pythagorean tuning, attributed to the ancient Greek philosopher Pythagoras (c. 570–495 BCE), who derived them from string lengths on the monochord, emphasizing pure fifths (3:2 ratio) as the basis for scale construction.[7] The major/minor classification for imperfect intervals developed later in medieval theory, notably with Guido of Arezzo (c. 991–1033), where intervals were integral to the modal system and organum polyphony.[7] The precise semitone measurements for major and minor intervals are as follows:| Interval | Minor (semitones) | Major (semitones) |
|---|---|---|
| Second | 1 | 2 |
| Third | 3 | 4 |
| Sixth | 8 | 9 |
| Seventh | 10 | 11 |