Publication date and place:1555 by Susato, Anvers.
Misc.: The first publication devoted entirely to Orlando di Lasso, commonly referred to as "Opus 1." In line with Lasso's somewhat cosmopolitan compositional predilections, it contains works in several languages and genres, including twelve Italian madrigals (a six-part sestina and six individual madrigals), six Villanesche, six French chansons, and six Latin motets.
In addition to being the first of a series of books that would soon launch Lasso to Europe-wide fame, this publication also has the notable distinction of containing the first known print of Cipriano de Rore's shockingly chromatic motet Calami sonum ferentes, placed by Lasso just after his own unusually chromatic Alma Nemes.
The book went through three editions, first in 1555 (RISM 1555-19), then c. 1558, then finally in 1560 (RISM 1560-4). The original 1555 edition has two variants, the second variant (apparently the result of a stop-the-press fix during the first printing) featuring slightly improved text-setting. An Italian variant of this edition (entitled "D'Orlando di Lassus il Libro Primo") also exists, although it is only extant in a single Superius part-book. The 1558 edition further improved the text placement, and the 1560 edition added the chanson Susanne un jour.