The tonic of note of a scale and is the first syllable, indicating the first tone of the ascending chromatic scale. In the "fixed Do" system, Do is always C. Do is the French, Italian and Spanish term for the pitchC.
See also
[Eng.]C;
[Fr.]Ut (m);
[Fr.]Do (m);
[Ger.]C (n);
[It.]Do (m);
[Sp.]Do.