John Cage's Song Books are a collection of short vocal solos, composed and put together in 1970. They were published in three volumes – Solos for Voice 3-58, Solos for Voice 58-92 and finally Instructions. Within this extraordinary work, there are four categories of solo: songs, songs with electronics, theatrical directions and theatrical directions with electronics.
The solos are composed in such a way that, as long as you are willing to be open-minded, there are almost limitless possibilties as to what you can do with each one. For instance, while some of them are in standard notation, not all solos indicate exact pitch – many display lines, giving an appoximate rise and fall, or ask you to use a route on a map to make your own vocal line. Others give you the option to change the notes to an appropriate clef for your range. Further scores are made up of numbers which the performer must alloclat by chance procedure to an action.