A person who composes music; a composer (of classical pieces, film scores, pop songs, etc.).
彼は若くして国際的に有名な作曲家になった。
He became an internationally famous composer at a young age.
その映画の音楽は女性作曲家が手掛けた。
The film's music was composed by a female composer.
作曲家として名前を残すことが彼の夢だ。
His dream is to leave a name as a composer.