Commentary Par XII 7-8

The previous tercet had divided the activity of the souls into circling movement and song; this one divides that song itself (repeating the word canto) into two components, words (muse) and melody (sirene).  Dante had used the word Muse (capitalized by Petrocchi, if we have little idea of Dante's actual practice with regard to capitalization) in [Inf I 7], in [Purg II 8] and [Purg XXII 102], then in [Par II 9], to indicate the Muses of classical antiquity.  Beginning here, however, and then in two later passages ([Par XV 26] and [Par XVIII 33]) Petrocchi obviously believes that Dante uses the lowercase word musa metaphorically, here to refer to poets (the next use will refer to Virgil [or his poetry] as 'nostra maggior musa' [our greatest muse], and finally [[Par XVIII 33]], to poetry itself – or so most readers believe).

Torraca (DDP Torraca.Par.XII.7-9) seems to have been the first to remark on the similar conjoining of Sirens and Muses in Boethius (Cons. I.1[pr]).  Aversano (b Aver.2000.2), p. 52, believes that the Muses inspire the words of the song, the Sirens, the music.

These two verses contain four words relating to music: canto (song), musa (muse), serena (siren), tuba (brass musical instrument [more precisely, 'horn']).  For the echoing effect that results from the repetition of the first two, Dante may have had in mind the similar effect found in Ovid's story of Echo and Narcissus, referred to inp Par.XII.14-15.  The next (and last) time we read the noun tuba (p Par.XXX.35*), it will be the metaphoric expression for Dante's poetic voice, while here it refers to the voices of the singing saints.