Since Terzaghi's edition (1939) no new relevant data were found illustrating the textual history of the Synesian poetic corpus from Late Antiquity to the Palaeologan Byzantium. Thanks to a new inspection of the main manuscripts and the enucleation of thematic and structural incoherencies, hitherto unnoticed, it seems possible to restore the structure of the hymnodic corpus as it was before its original pattern was damaged and modified by late Byzantine editors. Specific researches are devoted to: (1) the displacement of the ninth hymn (originally intended to open the hymns series); (2) the beginning of a new hymn with the last verses of the ninth; (3) the merging of two hymns into what is now the first hymn and a new assessment of the last part of the same piece (according to the Neoplatonic theory of the soul); (4) the real purpose and nature of the hymns 6-8 (uncorrectly considered "tout court" as christological), and the original structure of the eighth hymn (to be divided in two different poems). Moreover, the study of ancient and late antique metrical and musical theories reveals hitherto unexpected features about both production and performance of Synesius' hymns.