Referent of “one”
In the sentence “It is a highly unusual form of melody, one that occurs only in this composer’s work”, what is the referent of the pronoun ‘one’? Is it ‘melody’ or the entire prepositional phrase ‘form of melody’? Or, perhaps the referent is the subject of the sentence, ‘it’? I frequently hear the rule that the referent has to be the prior proximate noun.