player piano vs pianoforte

player piano and pianoforte both are nouns.

Word	Noun	Adjective	Verb	Adverb
player piano	Yes	No	No	No
pianoforte	Yes	No	No	No

As nouns, pianoforte is a hypernym of player piano; that is, pianoforte is a word with a broader meaning than player piano:

player piano: a mechanically operated piano that uses a roll of perforated paper to activate the keys
pianoforte: a keyboard instrument that is played by depressing keys that cause hammers to strike tuned strings and produce sounds

Other hypernyms of player piano include forte-piano, piano.

player piano (noun)	pianoforte (noun)
a mechanically operated piano that uses a roll of perforated paper to activate the keys	a keyboard instrument that is played by depressing keys that cause hammers to strike tuned strings and produce sounds