How do you not squeak on the tenor sax?

There are a few reasons you might be squeaking on the tenor saxophone. Make sure your embouchure is correct. The embouchure is the way you hold your mouth and lips on the saxophone mouthpiece. If your embouchure is too tight, you will produce a squeaky sound. If it's too loose, you will produce a breathy sound. The best way to find the correct embouchure is to practice in front of a mirror and make sure that your lips are covering the entire reed and that your teeth are not touching the mouthpiece.

Check the reed. If the reed is too soft, it may be more prone to squeaking. Try switching to a harder reed. If the reed is too old, it may also be more likely to squeak. Replace the reed if necessary.

Check the instrument. Make sure that all the screws and joints on the saxophone are tight. If there is a loose screw or joint, it can cause the saxophone to leak air and produce a squeaky sound.

Use a good quality mouthpiece. A cheap or damaged mouthpiece can also cause squeaking. If you are not sure if your mouthpiece is good quality, try switching to a different one.

Practice regularly. The best way to avoid squeaking is to practice regularly. The more you practice, the more familiar you will become with the correct embouchure and technique, and the less likely you will be to squeak.