Large 17th Century Antiphonal Music Leaf

Large painting on vellum, with seven bars of music in a square notation, lyrics hand scribed in Latin in black ink with red rubrics, having a large five line, intricately decorated illuminated initial in red and blue, from a 16th century (1650?) antiphonal
Frame size;
Length 54.5cm (1ft 10”)
Width 44cm (1ft  5”)