1. Cotton MS Tiberius B IX, ff 204–224 Reference (shelfmark): Cotton MS Tiberius B IX, ff 204–224 Title: John of Tewkesbury (attributed), Quattuor principalia (short version: 204r–214r, imperfect); treatise on music (215r–224v) Collection Area: Western Manuscripts Languages: Latin Date Range: 4th quarter of the 14th century Extent: 1 item