Sackbut eighteenth century; when it returned, the Italian term "trombone" became dominant. In modern English, an older trombone or its replica is called a sackbut. An older instrument generally differs from modern trombones by its smaller, more cylindrically-proportioned bore, and its less-flared bell. The bell section was more resonant (since it did not contain the tuning slide and was loosely stayed rather than firmly braced to itself). These traits produce a "covered, blended sound which was a timbre particularly effective for working with voices... zincks and crumhorns", as in an alta capella. The revived instrument had changed in specific ways. In
Musical instrument the twentieth century saw the gradual evolution of synthesizers—instruments that artificially produce sound using analog or digital circuits and microchips. In the late 1960s, Bob Moog and other inventors began an era of development of commercial synthesizers. One of the first of these instruments was the Moog synthesizer. The modern proliferation of computers and microchips has spawned an entire industry around electronic musical instruments. There are many different methods of classifying musical instruments. Various methods examine aspects such as the physical properties of the instrument (material, color, shape, etc.), the use for the instrument, the means by which music is