Sarah, the gray and black bird sounds like maybe a Junco to me. Does it have a whitish belly? Not the greatest photo, but something like this:
For what its worth, I'll tell you what works best for feeding here. Forget about the pre-made suet cakes. We've had them hang for weeks without any takers. Go to the meet counter or butcher shop and get some real beef suet. Don't let them give you the stringy yucky stuff, this is nice, solid suet.
As far as seed goes, we've had the best luck with black-oil sunflower seed. Just about all the different birds will eat it. The so called "wild bird" seed mixtures? Again, usually no takers. Might be different with Cardinals etc., but for Chickadees, Dovers, Finches, Grosbeaks, Nuthatches, even woodpeckers occasionally, you can't beat black-oil.
YMMV there in Michigan, but that's what works here in Maine. Oh yeah, the squirrels love it too!
