Serialism is a system developed most famously by Arnold Schoenberg to lend logic to a composition through the use of a fixed series of notes that must always appear sequentially whether in melody or harmony. Though most often associated with music that uses all 12 half-steps in a series (known as 12-note music), it can also be use with fewer notes. A branch known as total serialism used in the 1950s by Pierre Stockhausen also fixed the order of other musical events such as dynamics, rhythms, tempo, and even attack.