Slightly OT, but recently I changed blades on my miter saw, and "snugged" it (not "snug and a bit" as recommended above) since I am paranoid of breaking bolts.

The new blade, a Freud, completely changed the sound of the saw. Was the strangest sounding thing. Would whistle as it started much more slowly than before, then would sing as the blade spun down more slowly than before. I was thinking, how could a blade make the saw sound and run so differently!

I bet you have guessed what I did wrong by now...