Cantus. Of duos, or songs for tvvo voices, composed and made by Thomas Whythorne Gent. Of the which, some be playne and easie to be sung, or played on musicall instruments, & be made for young beginners of both those sorts. And the rest of these Duos be made and set foorth for those that be more perfect in singing or playing as aforesaid, all the which be divided into three parts. [...] - Whythorne, Thomas, (By Thomas Este, the assigne of William Byrd,, 1590)