In movable do, what is considered tonic?

• A. Any pitch can be tonic
• B. Do is always C
• C. Re is always D
• D. Mi is always E

Answer: (D)

The key idea is that movable do treats Do as the tonic, but the actual pitch of Do changes with the key. In this system, the tonic isn’t tied to a fixed pitch name like C; it’s the first degree of the scale in whatever key you’re in. That means Re, Mi, Fa, etc. are the second, third, fourth degrees relative to that Do, so Mi will sound as different actual pitches depending on the key (for example, in C major Mi is E, in A major Mi is C#, and so on).

The statement that Mi is always E would only hold if you were using a fixed-do system, where each syllable maps to a specific pitch name (Mi would always be E). In movable do, however, Mi’s actual pitch is not fixed—it depends on what the tonic Do is in the current key.