An apparatus is to assist an unskilled player in playing a musical instrument (2, 9, 10) by detecting (11, 12, 13, 15, 301, 302, 51, 605, 815) the quantity of the player's manipulation against the instrument (2, 9, 10), modifying (14, 16, 214, 216, 305, 503, 505, 514, 816, 902) the detected manipulation quantity with reference to a recommended manipulation (Sb) to a degree according to a given assistance coefficient (r, r2), and actuating (17, 18, 19, 20, 21, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 401, 402, 403, 404, 405, 406, 517, 603, 604) the instrument (2, 9, 10) with the modified manipulation quantity. For a brass instrument (2), the apparatus comprises an embouchure sensor (11) and a breath pressure sensor (12) to detect the embouchure and the breath pressure of the player as he/she plays the brass instrument (2). The detected embouchure and breath pressure are then modified with reference to a recommended embouchure and breath pressure weighted by a given assistance coefficient. The apparatus actuates the brass instrument based on the modified embouchure and breath pressure.