Titus Lucretius Carus - De Rerum Natura (On the Nature of Things)
Biblioteca Malatestiana in Cesena. Unfortunately I don't know how old this copy is.

Neume initial
Biblioteca Malatestiana, Cesena.

Jabir ibn Aflah (Geber) - Correction of the Almagest
Original is from the 12th century. Biblioteca Malatestiana in Cesena.