A single bifolio, very badly damaged by fire (warped and with holes). S-Sr 535 comes from a lost host manuscript to which the motet fragments S-Sr 813 and S-Sr 5786 may originally also have belonged. Two systems of three-voice score per page with traces of a gold-leaf initial. Parts of two, unique three-voice organa – Alleluia. Tumba sancti Nicolai and Terribilis est locus iste. Cumque evigilasset Iacob – probably from the mid-to-late thirteenth century. The notation is Franconian. Alleluia. Tumba sancti Nicolai (of which the initial Alleluia setting is lost, but the verse survives in full, and begins at the top of the page with a gold initial ‘T’) has two of its tenor pitches in red ink. These red notes have the function – described in Vitriacan treatises, but otherwise unknown in any other organa – of marking out pitches ‘alien’ to the original chant quotation. Alleluia. Tumba Sancti Nicolai is not a chant set in organum in earlier ‘Magnus liber’ sources (although a different two-voice organum setting is known from F-Pnm Latin 15129). Terribilis est locus iste. Cumque evigilasset Iacob, of which the beginning is missing, is a chant that receives organum settings in ‘Magnus liber’ sources (and S-Sr 535 shares a particular version of this chant tenor with the otherwise independent three-voice Terribilis est organum in I-Fl MS Pluteus 29.1).

Writing block of ca. 80 x 65 mm. Ruled red staves of five lines.

Two three-voice organum compositions (i.e. plainchant tenor with melismatic upper-voices). Both organa are incomplete and neither is known from other sources.