Two weeks later, German conductor Volker Hartung was arrested on the stage during a performance of the Cologne New Philharmonic. He was eventually released, but was banned from performing in France.

Miller told the Journal that the groups were providing music to small towns that would otherwise not be able to afford it. "Usually we're the only live opera of the season," he said. "They're thrilled to have us come."

Authorities and union leaders say that Hartung and Miller are taking away jobs from French musicians and exploiting their Eastern European counterparts. Miller rejected that argument, saying that his musicians "need the work, they don't hold out for high fees, and they play well."