aspen tree freeze
we live in aurora Colorado. this spring we had a late freeze and heavy wet snow. it seems that it froze the leaf buds. there are a few on the center trunk. some of the branches are dead, we have cut a few to check , do we trim the tree or leave it alone till next year and see if it comes around.
Adams County Colorado
You can check for green tissue just under the bark to assess if a branch is still alive. Normally if a branch is brittle that is also a good indicator. At this point branches which have not yet leafed out are likely dead and can be pruned out. A branch which is dead this year will not come back to life next year.
Sorry about your tree, it was a bad year for woody plants along the Front Range. If you have further questions please let me know.