1. Harley MS 3199, ff 74r-79r Reference (shelfmark): Harley MS 3199, ff 74r-79r Title: Guido of Arezzo, De tonis Scope & Content: Guido of Arezzo, De tonis Collection Area: Western Manuscripts Languages: Latin Date Range: 1st half of the 12th century Extent: 6 folios.
