Which musical style was a twentieth-century trend, particularly current in the period between the two world wars, in which composers sought to return to aesthetic precepts associated with the broadly defined concept of "classicism", namely order, balance, clarity, economy, and emotional restraint?

neoclassicism is the answer.

Explanation:

c, d, e, f, g, a, b, and c.

sometimes western music will also use solfege. the names of these are do ra me fa sol la si (or ti) and do.

to indicate a note a half step higher or lower then the original note, you would say c # (for a half a step above c) or bb (for half a step below b)