I have a Rheem rgdg-10eamer. While the A/C was running I heard the motor noise change in pitch several times. It may have been doing that all day when I wasn't home. Then the motor quite functioning. The air conditioner is still working outside.

I set the thermostat to heat and the blower motor worked fine. Any help is greatly appreciated.

If the inside blower is changing pitch try the following.

Open all registers
Make sure air filter is clean

If all that is OK then you have the option of calling for ON Site service or waiting till it stops working then call.