"Movable-Do" is a pitch notation system in music theory where the syllables "Do", "Re", "Mi", and so on, are used to represent the degrees of the diatonic scale. Unlike Fixed-Do, the pitches of these syllables are not fixed and instead vary based on the key or tonality of the music.
In the Movable-Do system, the syllable "Do" represents the tonic or keynote of the current key. This means that "Do" corresponds to the first scale degree of the major or minor scale in that key. The other syllables, "Re", "Mi", "Fa", "Sol", "La", and "Ti", represent the other scale degrees accordingly.
For example, in the key of C major, "Do" corresponds to the pitch of C, while in the key of G major, "Do" corresponds to the pitch of G.
Movable-Do allows musicians to easily identify the relative pitch relationships between notes within a given key. This system is particularly useful for sight-singing, ear training, and transposing music into different keys. By using Movable-Do, musicians can develop a strong sense of tonal center and better understand the harmonic structure of music.