Commentary Par XIII 25-27

In those two circles the souls were celebrating the triune God and, in the Person of Christ, His human nature as well (a song beyond our mortal understanding), not Bacchus or Apollo (songs all too understandable to us).  The word Peana may either refer to cries of praise to Apollo or, as seems more likely here, to the god himself.

For the program of song in the last cantica, see C.Par.XXI.58-60.