Less is known of the cornamuse than the crumhorn, since none have survived to present times. However, Michael Praetorius gives a description of the instrument in his Syntagma Musicum of 1618. It is essentially a "straight crumhorn" with a small resonating chamber rather than the flared bore, yielding a much softer tone. Like the crumhorn, it has a compass of just over an octavethough upward extension keys can be fitted to provide additional notes. The cornamuse blends very well with recorders; the bass is particularly useful, providing depth to a recorder consort.

Cornamusen are normally built to individual order, though a small stock is sometimes available. They can be provided in soprano, alto, tenor, bass and great bass sizes, with or without extension keys. Instruments are fitted with synthetic reeds (from the Renaissance Workshop, Bradford, UK) for ease of maintenance and trouble-free playing. A variety of timbers is available.