tonality vs major mode

tonality and major mode both are nouns.

Word	Noun	Adjective	Verb	Adverb
tonality	Yes	No	No	No
major mode	Yes	No	No	No

As nouns, major mode is a hyponym of tonality; that is, major mode is a word with a more specific, narrower meaning than tonality:

tonality: any of 24 major or minor diatonic scales that provide the tonal framework for a piece of music
major mode: a key whose harmony is based on the major scale

Other hyponyms of tonality include major key, minor key, minor mode, home key, tonic key.

tonality (noun)	major mode (noun)
any of 24 major or minor diatonic scales that provide the tonal framework for a piece of music	a key whose harmony is based on the major scale