divisio rhythmica

The term "divisio rhythmica" is an older classification of musical instruments, dating back to the 7th century, that includes both idiophones (instruments that vibrate on their own, like bells) and membranophones (instruments with a stretched membrane, like drums). These instruments are primarily used to emphasize or delineate rhythm in music. Rhythm itself is the organization of sounds in time, characterized by patterns of duration and occurring within a steady pulse or beat. While rhythm is fundamental to all music, it can exist independently of melody, as heard in drumbeats, whereas melody cannot exist without rhythm.12