Interactive theory · Lesson 8
Fixed-Do and Movable-Do: Two Ways to Count the Same Song
For the same song, when you change the key, the solfège syllables can either stay the same or change completely.
Did you know · In the first note of "Twinkle Twinkle Little Star" in C major, it's called Do. But in G major, that same first note is called Sol—the melody hasn't changed, so is it a mess? No. It's just two different rulers measuring different things.
The essence of a melody is the distance between adjacent notes, not its absolute pitch. Raising or lowering the entire song (a transposition) still sounds like the same song to your ears. However, the two solfège systems report different information: Fixed-Do reports the absolute address (which specific note "is this"), while Movable-Do reports its rank within the family (what position "this note holds").
The Core Rule of Movable-Do (Memorize This First):
The Tonic is the central note of the key, which corresponds to the note named in the key signature (G Major → Tonic is G; D Major → Tonic is D). Once you select the tonic:
Tonic = Do, followed by re, mi, fa, sol, la, si—
G Major: G(do) A(re) B(mi) C(fa) D(sol) E(la) F♯(si) G(do);
D Major: D(do) E(re) F♯(mi) G(fa) A(sol) B(la) C♯(si) D(do).
Therefore, to determine whether the opening of a melody is sung as "Do" or "Mi," look at its rank in the home key: if it ranks 1st, sing Do (as in "Twinkle Twinkle Little Star" and "Two Tigers"); if it ranks 3rd, sing Mi (as in "Ode to Joy")—this isn't rote memorization; it's derived logically.
The Tonic is the central note of the key, which corresponds to the note named in the key signature (G Major → Tonic is G; D Major → Tonic is D). Once you select the tonic:
Tonic = Do, followed by re, mi, fa, sol, la, si—
G Major: G(do) A(re) B(mi) C(fa) D(sol) E(la) F♯(si) G(do);
D Major: D(do) E(re) F♯(mi) G(fa) A(sol) B(la) C♯(si) D(do).
Therefore, to determine whether the opening of a melody is sung as "Do" or "Mi," look at its rank in the home key: if it ranks 1st, sing Do (as in "Twinkle Twinkle Little Star" and "Two Tigers"); if it ranks 3rd, sing Mi (as in "Ode to Joy")—this isn't rote memorization; it's derived logically.
Try it
How to Read the Table: The two rows for Movable-Do are identical (the house moves, but the ranking remains unchanged); the two rows for Fixed-Do are different (the absolute address changes). Use Fixed-Do for reading sheet music and fingering, while using Movable-Do for singing melodies aloud helps prevent going out of tune—teachers use both methods in class, and they don't conflict. Additionally: The vocals in the button above use Fixed-Do (pitch is fixed, so you sing what is written; in G major, the opening is sung as Sol)—the Movable-Do column is provided for your reference when singing aloud yourself.
After comparing a few more songs, you'll notice: The first solfège syllable in Movable-Do isn't always Do—it depends on whether the melody begins on the tonic. "Two Tigers" starts on the tonic, so its first syllable is Do; "Ode to Joy" starts on the 3rd degree, so its first syllable is Mi. But regardless of the song or key, the tonic is always sung as Do: