Mysterious Bird at Bird Feeder

I am sorry I do not have a picture of this bird. It is approximately the size of a grackle (possibly a little larger), it had a white tail, white ring around its neck and white on its chest. The rest of the bird appeared to be black. Its beak reminded be of a a cardinal's only it was dark and appeared to be longer. Can you help me? I live in Wisconsin and have never observed a bird like this before.

Thank you!