"En el arte de canto llano y canto de organo ay viente y un signos....", bound manuscript, music theory textbook, 160 pages, Spain(?), circa mid-18th century

A Spanish-language manuscript manual for learning plain chant, organ, and for more popular instruments like the guitar. Similar works were published in Spain as early as 1492, including Gonzalo Martinez de Bizcargui's Arte de canto llano y contrapunto y canto de organo, the 1543 edition of which, like this manuscript manual, contains a Guidonian hand illustration. Bonilla family provenance, though whether this family was resident in Spain or in Latin America is not known. There is a date of 1757 inside the front cover, as well as later inscriptions e.g., 19 August 1884 by Aniseto Bonilla.
The item is quite fragile and much of the text, save for the section headings, is badly faded. A digitized copy is available.