It is a MIDI sax offering real sax fingerings and a standard sax embouchure. Using alternate fingerings and adjusting the embouchure helps correct the pitch of these notes. Adjustments in the strength and shape of the embouchure change the tone and intonation (tuning). Subtle manipulation of embouchure and air pressure allows the oboist to express timbre and dynamics. In brass instruments, overblowing (sometimes combined with tightening of the embouchure) produces a different harmonic. The formation of the mouth around the mouthpiece and reed is called the "embouchure". Skilled oboists adjust their embouchure to compensate for these factors. They can also account for individual embouchure, oral cavity, oboe angle, and air support. The various octaves are produced using subtle variations of breath, finger positions and embouchure. Many saxophonists and pedagogues have published material on the saxophone embouchure and tone production. On a transverse flute this is generally done by narrowing the lip/embouchure. The orchestral double reeds all employ a similar embouchure. Students typically receive instruction in proper posture, hand position, embouchure, and tone production. Indeed, French flautist Marcel Moyse did not play with a symmetrical embouchure. Octaves are varied by manipulating one's embouchure and controlling the blowing strength.