American Percussion Works is a rare collection of seldom heard works each with specific rules or themes as a basis for the compositions. In John Cages First Construction the principle is based on the figure 16. Alberto Ginasteras work Cantata para América Mágica, uses pre-Columbian texts based on the conditions of human life, with war, natural phenomena, daybreak, night and love. Lou Harrison mixes non-European forms which follow the pattern of having a single melodic part accompanied (or enhanced) by rhythmic percussion in his Koncherto. Varèses Ionisation also enters a new land being his first solely percussive work where he finds a new grammar for the language of music.