NEW YORK (AP) ― While Lorin Maazel isn’t slowing down, his tempi are based on the performance of Verdi’s “Don Carlo’’ he led to mark the 50th anniversary season of his Metropolitan Opera debut.

Now 82, the former music director of the Cleveland Orchestra, Pittsburgh Symphony Orchestra and New York Philharmonic conducted an alternately elegant and disjointed opening of the revival Friday night.

The spectacle of the third act auto-da-fe was spacious, the trumpets grand. Confrontations were charged.

Other moments slowed to a crawl, such as Eboli’s “O don fatale’’ and Elisabeth’s “Tu che le vanita,’’ sapping the drama. There were tentative entrances, with the singers having trouble adjusting to his pacing. But overall, it was a largely effective account of Verdi’s longest work, which stretches over five acts and 4 1/2 hours.

Maazel has spanned several generations ― his November 1962 Met debut in Mozart’s “Don Giovanni’’ featured a cast that included Cesare Siepi in the title role. After that season, when he also conducted Strauss’ “Der Rosenkavalier,’’’ Maazel did not return to the Met until a revival of Wagner’s “Die Walkuere’’ five years ago.

“Don Carlo,’’ based on Friedrich Schiller’s play, details the court of 16th century Spain. King Philip II, son of the Holy Roman Emperor Charles V, married the French Princess Elisabeth de Valois, who had been engaged to Philip’s son, Carlo. There is tension between the crown and the church, and Philip’s court is filled with rebellion and affairs.

Maazel was given a top cast, with Ramon Vargas in the title role, Dmitri Hvorostovsky as Rodrigo, Ferruccio Furlanetto as Philip II, Barbara Frittoli as Elisabeth, Anna Smirnova as Eboli and Eric Halfvarson as the Grand Inquisitor.