Le istitutioni harmoniche : nelle quali oltra le materie appartenenti alla musica : si trouano dichiarati molti luoghi di poeti, d'historici, & di filosofi : si come leggerle si potrà chiaramente vedere
Le istitutioni harmoniche is a 1558 Venetian music theory treatise by Gioseffo Zarlino, a sixteenth-century Venetian theorist, written for students and scholars of musical tuning. Its pictures are plain black-and-white diagrams of tetrachords and scale ratios drawn as labelled arcs above and below rows of numbers, with Greek and Italian terms; a designer could borrow their clean, schematic structure of nested curves for abstract linework or geometric diagrams.
