1. (noun) (music) the first note of a diatonic scale

• tonic

1. (noun) the principal theme in a speech or literary work

• subject
• theme
• topic

2. (noun) a fundamental or central idea

• idea
• thought

3. (noun) (music) the first note of a diatonic scale

• musical note
• note
• tone

4. (verb) set the keynote of

• set

5. (verb) give the keynote address to (an audience)

• address
• speak

1. (noun) (music) the first note of a diatonic scale

• c

1. (noun) (music) the first note of a diatonic scale

• music