KATONAH, New York (AP) ― It’s been called the “missing link’’ among Giuseppe Verdi’s operas, composed right after his three mid-career mega-hits ― “Rigoletto,’’ “Il Trovatore’’ and “La Traviata’’ ― and pointing the way toward the masterpieces of his later years.

Why “missing?’’ It’s not as if “Les vepres siciliennes’’ (“The Sicilian Vespers’’), first performed in Paris in 1855, was lost or had to be reconstructed by scholars. Yet, despite its importance in the Verdi canon, the opera has remained a relative rarity.

Now, in the great Italian composer’s bicentennial year, “Les vepres’’ is getting renewed attention, with performances this summer in Frankfurt, Germany, and at the Caramoor Festival outside New York City, plus a much-anticipated production at London’s Covent Garden this fall.

“Those three works right before it are shorter, perfectly proportioned, the summing up of everything he already knew how to do,’’ said Will Crutchfield, Caramoor’s director of opera. “After that, he felt a need for taking in some other possibilities.’’

Paris in those days represented the pinnacle of success for an opera composer, with lucrative contracts and a history of productions that were heavy on spectacle, like Rossini’s “William Tell’’ and the operas of Giacomo Meyerbeer.

“He wanted something with big, grandiose effects, and that’s what he did,’’ Crutchfield said in an interview after a rehearsal this week. “And he did a great job of it. The music is fantastic.’’

Indeed it is. Beyond the best-known numbers, like the heroine’s bolero and “Et toi, Palerme’’ for the bass, the entire score teems with inspired arias, duets and ensembles.

Verdi enlisted a frequent Meyerbeer collaborator, Eugene Scribe, to write the libretto, based on historical events of the 13th century when the Sicilians rose up to overthrow their French rulers. Tradition says the rebellion was signaled by the ringing of bells for sunset prayers known as vespers. In the opera, the bells mark the wedding of the lovers Helene and Henri, who support the uprising even though Henri is the son of the French governor, Montfort.

“I think it’s the most political opera that Verdi wrote,’’ said Norbert Abels, chief dramaturg of Oper Frankfurt, where a new production has been drawing packed houses. “Sure, there’s a love story, but it’s not the main point.