songwriter vs songster

songwriter and songster both are nouns.

Word	Noun	Adjective	Verb	Adverb
songwriter	Yes	No	No	No
songster	Yes	No	No	No

As nouns, songwriter and songster are synonyms defined as:

Other synonyms of songwriter include ballad maker.

songwriter (noun)	songster (noun)
a composer of words or music for popular songs	any bird having a musical call
	a person who sings with skill
	a composer of words or music for popular songs