from The Century Dictionary.
- noun A book containing music for a choir or chorus.
Sorry, no etymologies found.
The first step in the evolution of the Breviary was the separation of the Psalter into a choir-book.
This instance is taken from a large choir-book, probably of French, certainly of
It occurs in the choir-book of the monks of St. Gall in Switzerland, and was probably composed by Notker, surnamed the St.mmerer, about the end of the ninth century, or the beginning of the tenth.
 a hired shepherd, or hidden himself under the cowl in a cloister; and Raphael, as if at work on choir-book or missal, still applies symbolical gilding for natural sunlight.