As part of the ancient roman army, the cornicen sounded signals on an instrument called the

They played the Cornu, a horn-like instrument.

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)