Sergei Rachmaninoff vs composer

Sergei Rachmaninoff and composer both are nouns.

Word	Noun	Adjective	Verb	Adverb
Sergei Rachmaninoff	Yes	No	No	No
composer	Yes	No	No	No

Sergei Rachmaninoff (noun)	composer (noun)
composer and piano virtuoso born in Russia (1873-1943)	someone who composes music, usually as a profession