Ma spoke from experience, citing the experiences of two members of his Silk Road Ensemble who have faced repeated hassles entering the U.S. Iranians Siamak Aghaei and Siamak Jahangiri have visited the country eight times with the Silk Road Project since 2000, but must still wait months before receiving visas. They are required to fly to Dubai for a consular interview, then fly back to collect the visa.

Tony Edson, the State Department's deputy assistant secretary for visa services, defended the government's record on visas, testifying that personal interviews are an "incredibly useful" security tool, according to the Times.

Edson said 515 consular jobs had been created since September 2001 and that the State Department has become more efficient thanks to improved training and computer systems. Paperless visas and digital video interviews are under consideration.

European musicians fare only slightly than their Middle Eastern counterparts: The Manchester-based Hall_ Orchestra recently announced that the hassle and expense of obtaining visas in London had forced it to cancel a U.S. tour scheduled for 2007.

Ma, who was born in Paris to Chinese parents, moved to the United States at age 7.