A device, system, and methods for indicating trombone slide positions is disclosed. Namely, a trombone slide position indicator is provided. In some embodiments, the trombone slide position indicator includes a slide position rod mounted in a fixed position in relation to the outer slide of the trombone. Further, a plurality (e.g., seven) slide position indicators are provided along the length of the slide position rod, wherein the positions of slide position indicators correspond to a certain pitch or note. A sensor guide is mounted to the outer slide, wherein the sensor guide moves with the outer slide and in relation to the fixed slide position rod. The sensor guide includes a mechanism for detecting and/or indicating close proximity to any one of the slide position indicators along the slide position rod. Further, a method of using the trombone slide position indicator is provided.