concert pitch vs international pitch

concert pitch and international pitch both are nouns.

Word	Noun	Adjective	Verb	Adverb
concert pitch	Yes	No	No	No
international pitch	Yes	No	No	No

As nouns, concert pitch and international pitch are synonyms defined as:

concert pitch and international pitch: the pitch used to tune instruments for concert performances; usually assigns 440 Hz to the A above middle C

Other synonyms of concert pitch include philharmonic pitch.

concert pitch (noun)	international pitch (noun)
the pitch used to tune instruments for concert performances; usually assigns 440 Hz to the A above middle C	the pitch used to tune instruments for concert performances; usually assigns 440 Hz to the A above middle C