In mathematics, a well-defined action that, when applied to any permissible combination of known entities, produces a new entity, e.g. , the process of addition in arithmetic--in adding 5 and 3 to obtain 8, the numbers 5 and 3 are the operands, the number 8 is the result, and the plus sign is the operator indicating that the operation performed is addition. See operator, unary operation, binary operation.
In music an basic operation is one which may be performed on a set of pitches or pitch classes, including transposition, inversion, and multiplication. These may be combined to form compound operations, and inversion may be more accurately thought of as the compound operation transpositional inversion. See: transformation, counterpoint.
