leitmotif vs melodic phrase

leitmotif and melodic phrase both are nouns.

Word	Noun	Adjective	Verb	Adverb
leitmotif	Yes	No	No	No
melodic phrase	Yes	No	No	No

As nouns, melodic phrase is a hypernym of leitmotif; that is, melodic phrase is a word with a broader meaning than leitmotif:

leitmotif: a melodic phrase that accompanies the reappearance of a person or situation (as in Wagner's operas)
melodic phrase: a succession of notes forming a distinctive sequence

Other hypernyms of leitmotif include air, line, melodic line, melody, strain, tune.

leitmotif (noun)	melodic phrase (noun)
a melodic phrase that accompanies the reappearance of a person or situation (as in Wagner's operas)	a succession of notes forming a distinctive sequence