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 Cage's First Construction the principle is based on the figure 16. Alberto Ginatera's work Cantata para America Magica, 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. Varese's Ionisation also enters a new land being his first solely percussive work where 'he finds a new grammar for the language of music.'