Reading the transcriptions

"Duple Proportion is, when to a Stroke, or Semibrief-time, is sung 2 Minims... one to Thesis or Fall, and the other to Arsis or Rise of the Hand"

(CB.24)

'Binary measuring of the notes':

     "Niderschlag" = 'downbeat'

     "Auffschlag" = 'upbeat'

(MB. unnumbered extra folio after L iv)

'What is the sign of Duple measure?'

'A half-circle with, or without, a stroke. '

(MB.Biiiv)