Easton's Bible Dictionary (1897)
Heb. shophar, “brightness,” with reference to the clearness of its sound (1 Chr. 15:28; 2 Chr. 15:14; Ps. 98:6; Hos. 5:8). ” It denotes the long and straight horn, about eighteen inches long. The words of Joel, “Blow the trumpet,” literally, “Sound the cornet,” refer to the festival which was the preparation for the day of Atonement. In Dan. 3:5, 7, 10, 15, the word (keren) so rendered is a curved horn.
The word “cornet” in 2 Sam. 6:5 (Heb. mena’an’im, occurring only here) was some kind of instrument played by being shaken like the Egyptian sistrum, consisting of rings or bells hung loosely on iron rods.
Smith's Bible Dictionary (1863)
(Heb. shophar), a loud-sounding instrument, made of the horn of a ram or a chamois (sometimes of an ox), and used by the ancient Hebrews for signals, (Leviticus 25:9) and much used by the priests.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
COR'NET. 1 Chr 15:28. An instrument of music about 18 inches long, used by the priests, and giving a loud, smooth sound.