Passage 9.17.7
τοὺς δὲ παρὰ τὸ Ἀμφίονος μνῆμα λίθους, οἳ κάτωθεν ὑποβέβληνται μηδὲ ἄλλως εἰργασμένοι πρὸς τὸ ἀκριβέστατον, ἐκείνας εἶναί φασι τὰς πέτρας αἳ τῇ ᾠδῇ τοῦ Ἀμφίονος ἠκολούθησαν· τοιαῦτα δὲ ἕτερα λέγεται καὶ περὶ Ὀρφέως, ὡς κιθαρῳδοῦντι ἕποιτο αὐτῷ τὰ θηρία.
The stones near the tomb of Amphion, roughly placed beneath it and with no precise craftsmanship, are said to be the very rocks that once followed Amphion's singing. Similarly, stories are told about Orpheus also, how wild beasts would follow him when he played the lyre.