When two or more things happen at the same time, they occur concurrently. If the concerts you want to attend are happening concurrently, you have to choose one — unless you know how to be in two places at the same time.
The adverb concurrently comes from the Latin word concurrere, meaning “to run together,” or “assemble hurriedly.” If you’re ever lucky enough to go to the Olympics, you’ll find that many events are scheduled concurrently, so you may not be able to see the Norway/Sweden curling match, the biathlon, freestyle skiing and the couples figure skating if they are all at the same time. That will be a tough choice.
