Help please, birdlovers

I've noticed a new kind of bird at my feeder today; they're bluish-gray with a white breast, and they have a little bit of a topknot like a bluejay.  They're not that big, though.  More the size of my house finches.   That's a house finch on the left side of the feeder. 

Thank you, faithful reader!  That bird is a tufted titmouse!