The sound mass technique pioneered by such works as Ruth Crawford Seeger's String Quartet (1931) and Iannis Xenakis's Metastasis (1955) is fundamentally an elaboration of the tone cluster. Historian and critic Kyle Gann describes the broad range of ways in which Cowell constructed (and thus performed) his clusters and used them as musical textures, "sometimes with a top note brought out melodically, sometimes accompanying a left-hand melody in parallel.". At least as far back as 1942, John Cage, who studied under Cowell, began writing piano pieces with cluster chords; In the Name of the Holocaust, from December of that year, includes chromatic, diatonic, and pentatonic clusters. The site may not work properly if you don't, If you do not update your browser, we suggest you visit, Press J to jump to the feed. Groups of notes like this can be difficult to read, and in many cases specific pitches are not required. Clusters may be performed with almost any individual instrument on which three or more notes can be played simultaneously, as well as by most groups of instruments or voices. //