From Wiki:
A shofar (pron. /ʃoʊˈfɑːr/, from Hebrew: About this soundשׁוֹפָר (help·info), pronounced [ʃoˈfaʁ]) is an ancient musical horn typically made of a ram’s horn, used for Jewish religious purposes. Like the modern bugle, the shofar lacks pitch-altering devices, with all pitch control done by varying the player’s embouchure. The shofar is blown in synagogue services on Rosh Hashanah and at the very end of Yom Kippur, and is also blown every weekday morning in the month of Elul running up to Rosh Hashanah. Shofars come in a variety of sizes and shapes, depending on the choice of animal and level of finish.