I'm presuming this is some kind of flycatcher. He didn't stay around long and I haven't seen one around the feeding station before. The breast is pale yellow... not really showing up that way here.
This is an Eastern Phoebe. It's the only flycatcher that is (supposed to be) here in the eastern U.S. in winter, because they eat a lot of fruit in winter. The dark cap, dark bill, gray upperparts, and light belly (which usually does show a pale yellow wash, as here) are key marks. You also undoubtedly noticed its characteristic tail flipping behavior and may have heard its very rich, loud, chip note.