What is a closed line that can be geometric?

Nstrumental music that supports the main part(s) chamber music 2. a large group of instruments usually including woodwinds, brass, and percussion band 3. music written for small ensembles for an intimate setting accompaniment 4. a person who leads an ensemble conductor 5. an electronic keyboard capable of multiple instrument sounds

Neon colours names?sorry if my english are bad

Be-bop is jazz intended for listening, not dancing? true or false