Note 11 — Chapter V · THE CAROLINGIANS AND THE TENTH CENTURY
Reading edition
Above, page 110. The distinction seems to be made by Walafrid Strabo, Libellus de exordiis et incrementis rerum ecclesiasticarum (840-842), cap. 26, pp. 506-508 (MGH, Capitularia regum francorum, II, Appendix); and by Hucbald (IXth century):
Astipulare meis, quia non sunt carmina, rhythmis ... Quod si, ut puto, nequit carmen jam jure vocari, Sit satis huic saltem censeri nomine rithmi.
Quoted by Desilve, De schola Elnonensi Sancti Amandi, p. 57.