Striking Radio City Music Hall (search) musicians were instructed by their union Thursday to perform at the famed "Christmas Spectacular." (search) But management said it was going forward with recorded music.

A preseason performance Wednesday night was canceled and ticketholders were left disappointed as several dozen musicians picketed outside the Manhattan landmark. Stagehands also walked out in support.

The labor strife cast a cloud of uncertainty over the "Christmas Spectacular" — a show, featuring the Rockettes (search) precision dance group, that has entertained children and adults for seven decades.

On Thursday morning, a phone hotline at Local 802 of the American Federation of Musicians told members: "All Radio City Hall musicians are scheduled to play the 11 a.m. performance on Thursday, and are to report to the stage door at 10:30, dressed and ready to work."

However, a management spokeswoman said Radio City was "moving forward with a 55 piece recorded world class musical score."

"The musicians went on strike and did not show up for rehearsals, so they cannot then decide to come back on a whim or without a contract," said spokeswoman Mikyl Cordova.

The musicians walked out Wednesday. The main issues are salaries and overtime pay. The orchestra's contract expired in May, and the union blamed Radio City Entertainment, which produces the Christmas show, for the breakdown of talks.