Early on, DJ Shazam encouraged concertgoers to dance, and many did. But Zankel wasn’t quite the place for that. It could be, though. Whatever happened to the flexibility of configuration that was one of this hall’s selling points? One configuration had a flat floor and no seats, and that is exactly what was needed here. When you have a hall that can be made to suit any musical circumstance, it seems awfully silly to force that variety into a configuration best suited to chamber music concerts.