- The general pitch that an instrument is known for; the overall stretch of an instrument’s voice. For example, the cello has a lower register than the violin*. In sheet music, register is signified by a clef.
- In organ music, a register is a set of pipes (or “rank” of pipes) of one length, responsible for a specific octave or timbre. In stringed keyboard instruments, a register is a choir of strings.
- Organ stops may be referred to as registers; the act of alternating stops is called “registration.”
* (Not to be confused with range, which is the exact amount of notes an instrument is capable of producing. While the violin has a higher register than the cello, they both cover a total of about 4 octaves.)