I have got quite a collection of saxes, vintage through to modern but I don't understand why diferent saxes seem to have such different tuning tendencies when I play them. I have just bought from Milandro a lovely Mauriat alto - great tone and nice action. But when I blow it with a variety of mouthpieces I find that the upper octave is generally about 10-20 cents sharper than the lower octave. This is (honestly) with no alteration of the embouchure when going between octaves, just use of the octave key. And the difference holds true wherever the mouthpiece is positioned - in tune down below means sharp up top, in tune up top means flat down below. This is the same thing I have experienced on other nice horns like Keiwerth SX90R (alto and tenor) and Maxtone (alto and tenor) - good saxes which seem almost identical to the Mauriat. Upper octave tending to be noticeably sharper than lower octave. My usual alto and tenor are MkVIs and the octaves are pretty even (say within 5 cents), although there are rogue notes in each register. Many other saxes I have played tend to follow the Selmer intonation tendency for me. That includes Buffet S1 (alto), Grassi (alto & tenor), Walstein (alto), Yamaha (alto). So those ones have got reasonably in tune octaves. Can it be that I play better in tune on "Selmer-style" bore saxophones and out of tune on larger bore horns ? And if so, what is going on ? Rhys PS I would love to play the Keilwerths and Mauriat a bit (for their tone), but not if that means learning a whole set of playing adjustments that just mess up my playing on the Selmers.