Subject: Why do ceiling fans make a saxophone have a wavering sound?

In a band rehearsal recently, we noticed that when someone played the saxophone
in a room with a ceiling fan turned on, it made a wavering sound.  When the fan was 
turned off, it sounded normal again.  Other electronic instruments did not seem
to be affected.  I am thinking it might be that sound waves hitting the fan
blades may be out of phase with waves that don't hit the fan.  Much the same
effect as a whirling speaker in a Leslie amplifier.  Is that correct?

Re: Why do ceiling fans make a saxophone have a wavering sound?