Music Macro Language
Music Macro Language (MML) is a set of programming-language commands for generating computerized music. It is regarded as having "classical" and "modern" varieties. MML originated with Japanese video games of the 1970s, and a form of it was incorporated into Microsoft BASIC versions of that era, where they are typically expressed as a MUSIC command with a string expression as its argument, where the string has the MML code consisting of a series of letters and numbers expressing notes and their lengths.
Music Macro Language is sometimes confused with Music Markup Language, an XML-based language for describing music, but they are different.