In Liber IV 'Magia Musica' Gasper Schott deals with divisions and definitions of practical music, explained mathematically. Fig. I–IV shows how the mathematical basis for the major scale can be demonstrated by dividing the monochord string into up to 6 equal parts. Fig. V explains the intervals to be achieved through ratios comprising the numbers 1–6. (Greek interval names are used: Diapason = Octave; Diapente = 5th; Diatesseron = 4th etc.).