A hybrid saxophone is a combination of an acoustic saxophone and an electronic system, and the electronic system includes key sensors for monitoring the keys and a tonguing sensor for detecting the position of the tongue together with a breath sensor and a lip sensor, and the pieces of playing data are brought to an electronic tone generator for producing electric tones; the mouthpiece of the acoustic saxophone is replaced with another mouthpiece, which does not supply the breath to the reed, and a rotary type air-flow regulator is provided in the mouthpiece so that the player feels the blowing same as that in the acoustic saxophone.