Commentary Par XXIII 56

Polyhymnia is mentioned as one of the nine Muses by all the early commentators; most of them go on to identify her with memory rather than a specific artistic form, as she is in handbooks today (with the sacred hymn).  The first commentator to associate her with hymns was Andreoli (DDP Andreoli.Par.XXIII.55-57), etymologizing her Greek name; with him she becomes, for the modern commentary tradition, the Muse 'of many hymns.'