Bananafan:

Your apple tree is still asleep for the winter.

Lop off the two shorter branches where they attach to the trunk and train the remaining branch as a central leader. Pound in a 4' stake next to it and loosely tie it to the stake with green landscape tape. Strip the leaves off of it and bend the tip down below horizontal, tying it in place. This will cause the rest of the tree to sprout branches; as they sprout out, clip a clothes pin right above it to make it grow out horizontally. Some of these may blossom this year in May. You will get a bunch of apples next year; thin these to one apple in 8" for the best size.

Good news, Applenut. I did what you suggested and the tree is now throwing out several new shoots. My question is, should I continue to tie the tip of the central branch down below horizontal level to the stake, or should it be removed at some point when the branches all grow out? I'm so excited to see the new growth and can't wait to see it fruiting this May. Thanks so much and look forward to your further advice.