After working almost three years without a contract, many public school principals aren’t exactly jumping at the chance to spend a Saturday morning with their boss, the schools chancellor.

So Joel Klein is trying a novel approach to lure principals to a citywide meeting focusing on changes to the school system: offering free tickets to Broadway hits like “Hairspray” and “Sweeney Todd.”

The president of the principals union, Jill Levy, called the offer “disgraceful.”

The meeting, scheduled for this Saturday, is not mandatory because under union contract rules the city cannot require principals to attend events at times other than during the normal workweek.

“I think it’s ridiculous,” a principal at Public School 101 in East Harlem who is skipping the meeting, Alexander Castillo, said. “Don’t give me tickets, give me a contract.” He said Saturday meetings have always been “sort of taboo.”

The tickets, costing $60 apiece, are being paid for with an anonymous donation made to a discretionary fund controlled by Mr. Klein.

Every principal who shows up on Saturday is entitled to two free tickets to one of the following shows: “Bridge and Tunnel,” “Chicago,” “Dirty Rotten Scoundrels,” “Doubt,” “Hairspray,” “The Producers,” or “Sweeney Todd.”

So far, about 340 of the city’s 1,400 principals have agreed to attend, the Department of Education said. Today is the last day principals can request tickets.

“The tickets are a token of appreciation,” a spokesman for the education department, David Cantor, said. In a last-ditch recruitment effort, the department started calling principals yesterday to remind them about the meeting.

Mr. Klein first mentioned the event in a letter to principals sent earlier this month, and he followed up last week with an official notice and information about the Broadway tickets.

The union quickly sent out a letter of its own, reminding principals that they were under no obligation to attend a Saturday meeting. Ms. Levy said the city is barred from taking attendance and could not penalize educators who did not show up.

“My feeling is that if I was the chancellor, I would never be so disrespectful as to do this on a Saturday – I would take the dog and pony show to the regions,” Ms. Levy said.

“Do you know what? A principal can afford to buy a theater ticket, for goodness sake,” she said.

The city’s principals earn about $100,000 to $125,000 a year.

“Jill Levy is upset because so many principals want to go,” Mr. Cantor said about the meeting. “The reason it’s on a Saturday is because we needed to attract as many principals as we could and we thought that on a Saturday we would have the most luck doing that.”

Mr. Klein is also flying in a speaker from London who advised Prime Minister Blair and is now consulting for the city’s education department, Sir Michael Barber.

Tensions are riding high as the union representing principals, the Council of School Supervisors and Administrators, is coming up on its third year without a contract. The union recently declared an impasse in contract negotiations with the city and asked a state mediator to help end the dispute.

Mr. Klein intends to use the meeting on Saturday at the Rose Theater at Lincoln Center to inform principals about his new accountability measures, including grading every school on a scale of A to F. Principals at schools that continually receive a failing grade could be removed from their posts, Mr. Klein said when he first announced the changes at Tweed Courthouse earlier this month.

The announcement angered Ms. Levy, who said that any removal of principals based on new grades would have to be negotiated in a new contract.

“If the information is of such import, you wouldn’t hold a meeting on a Saturday,” the principal of the highly regarded P.S. 234 in TriBeCa, Sandra Bridges, said yesterday. She said she will be heading out to the country for the weekend and does not plan to attend the event.

Asked if she felt upset that she would be missing out on free tickets, Ms. Bridges said, “I hate musicals, and usually plays are a little too long for me.”