1. Vocal music is music that uses and focuses on the human voice. It's the opposite of instrumental music, which uses instruments like brass or percussion instead of the voice. ... Some vocal music is done a cappella, which is music that uses just human voices with no instrumental accompaniment.
2. Strictly speaking, it is not necessary to learn an instrument to become a singer/vocalist. It doesn't help increase vocal range or intonation. Even music theory is not necessary.
