When I want to know the duration of a concert, which is a more idiomatic expression?<br/><br/>1. How long is the concert?<br/><br/>2. How long does the concert las?<br/><br/>3. How long is the duration of the concert?<br/><br/>3. What is the duration of the concert?<br/><br/>Or are there other options?<br/><br/>Many thanks.<br/><br/>Donna