Typically the only thumb key found on most saxophones, the octave key might be the most important key on the alto sax. It is crucial that the octave key functions properly. There are a number of reasons for an octave key to stop working correctly, such as impact damage and general wear and tear. You can easily fix most malfunctioning octave keys without any special training.
Inspect the octave key to determine the problem. Watch the pad while pressing the key and letting it go to see whether it opens far enough or does not close completely.
Remove the neck from the saxophone. Make sure the octave key lever at the top of the saxophone’s body still has a plastic sleeve where the lever contacts the bottom of the key on the neck.
Bend the top part of the octave key with your fingers to align the pad. Hold the key open and press down if the pad is not closing all the way. Press up if the pad is not opening all the way. Reassemble the saxophone.
Play a high G. The octave key on top of the neck should stay closed. Locate the high G octave pad. On most saxophones, it is beneath the levers at the top of the body, opposite the palm keys. It should open when you finger high G and close all the way when you finger high A or above.
Inspect the levers between the thumb key and the high G octave pad. Take the instrument to a professional repair shop if one or more levers is damaged or misaligned.
Clear any obstructions from the octave key openings using a pipe cleaner. Bend the pipe cleaner into an L shape and insert it through the hole on top of the saxophone neck. Finger a high G to open the G octave pad and insert the pipe cleaner.
A severely damaged or misaligned octave key may require professional repair.
Take care when bending an octave key to avoid snapping it in half.