FILE - This Sept. 8, 2008 file photo shows Maestro Riccardo Muti leading the Vienna Philharmonics, in Lucerne, Switzerland. It isn't every day that a conductor concedes an encore for an opera chorus. Even rarer is asking the audience to sing it, but maestro Riccardo Muti has just done so for the love of homeland. Muti swirled about on his podium late Saturday, March 12, 2011 to face the audience during Giuseppe Verdi's "Nabucco'' at Rome's Teatro dell'Opera when shouts of "bis!'' (encore!) rang out.  (AP Photo/Keystone, Sigi Tischler, file)

Photo by: SIGI TISCHLER

FILE - This Sept. 8, 2008 file photo shows Maestro Riccardo Muti leading the Vienna Philharmonics, in Lucerne, Switzerland. It isn't every day that a conductor concedes an encore for an opera chorus. Even rarer is asking the audience to sing it, but maestro Riccardo Muti has just done so for the love of homeland. Muti swirled about on his podium late Saturday, March 12, 2011 to face the audience during Giuseppe Verdi's "Nabucco'' at Rome's Teatro dell'Opera when shouts of "bis!'' (encore!) rang out. (AP Photo/Keystone, Sigi Tischler, file)