Note Name · Theory

Pitch Octave Semitone and Whole Tone Scale Key Signature

Pitch is a continuous slope; note names are posts driven into it. The posts exist for one purpose: so that different people, at different times, can refer to the same pitch. Which is why "note name" is never one system but three running in parallel.

What each system is for

System	Used for	Example	Property
Letter names	Notation, instrumental parts, international exchange	C D E F G A B	Independent of key; one pitch, one name, always
Solfège syllables	Sight-singing, teaching, ear training	do re mi fa sol la si	Fixed or movable depending on the method
Chinese pitch names	Tuning theory, traditional music scholarship	Huangzhong, Dalü, Taicu, Jiazhong …	From the twelve-lü system, derived from pipe lengths

Letter names are the international set. Solfège splits into two practices: fixed do nails do permanently to C, while movable do nails do to the tonic of the current key. The same melody sung both ways produces completely different syllables.

The Chinese twelve pitch names — Huangzhong, Dalü, Taicu, Jiazhong, Guxian, Zhonglü, Ruibin, Linzhong, Yize, Nanlü, Wuyi, Yingzhong — are a separate lineage, derived from the lengths of pitch pipes rather than from the Western twelve-tone system. A few of these names appear again in pentatonic scale and scale. Genre-level usage belongs to a different site.

The semitones hide between two letter pairs

Among the seven letters, only two adjacent pairs are naturally a semitone apart:

C — D — E ⌒ F — G — A — B ⌒ C
    whole   half   whole  whole  half

There is no black key between E and F, or between B and C — those pairs are semitones in themselves. The remaining steps, C–D, D–E, F–G, G–A and A–B, are whole tones. Remember these two gaps and every key position follows: the three-white-key cluster C–D–E has the E–F gap on its left; the B–C gap sits on the left of the two-black-key group.

Diagram: letters, syllables and the keyboard

Listen: matching names to what you hear

Walk up in note-name order. Each name corresponds to a fixed height, while solfège syllables move with the key.

Common misconceptions

"do re mi just means C D E." Only inside C major, and only temporarily. In movable do, F major starts on do = F; in fixed do, F major still has do = C.
"Twelve pitches, so twelve letters." There are only seven letters. The twelve pitch positions are built on those letters with accidentals (sharps and flats); the alphabet itself never grows.
"The Chinese twelve-lü are equal temperament." They are not. Twelve-lü is a system of twelve named pitches, which is a different claim from "every semitone is equal."
"A black key was left out between E and F." Nothing was left out. The seven letters were never evenly spaced; the keyboard simply draws that honestly.

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Listen in the library

Scales, Arpeggios, and CadencesC13:22Scales and arpeggio exercises — step up in note-name order and link the names to what you hearDetailsHanonC21:36A Hanon piano exercise — a fixed note-name sequence inside one hand position, easy to check phrase by phraseDetailsOld 100thC10:23The hymn tune "Old 100th" — only the seven note names of the key, with no accidentalsDetails

All tracks from midicn-lib — inline badge is the license tier (C1 commercial / C2 non-commercial / C3 study only).

Sources

字母音名、唱名体系、中国十二律名的名称与排列，属通行乐理与律学常识
唱名法（首调 / 固定调）的区分依通行教学体系表述，本文行文为原创

Used for fact-checking only; all prose is original.

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