David Rosen walked into France’s Bibliotheque Musee de l’Opera National during the summer 1968, and asked for the original materials that were available from the time Giuseppe Verdi’s opera “Don Carlos” was first performed at the Paris Opera in 1867.

The Opera’s manuscript score was handed to the musicologist. He discovered several sections, including an unknown passage between King Philippe II, Rodrigue, and the Marquis de Posa. This passage was not in the original score that Verdi had written. Verdi deleted the passage and clasped it before the opening night so that the audience could catch the last train to the suburbs at 12:35 AM.

The 83-year old retired Cornell professor recalled that “it was hiding in plain view” to The Associated Press.

After 217 performances of “Don Carlo” in Italy, the Metropolitan Opera will present the original French version. The 8th and final performance on Monday night will be broadcast to cinemas around the world.

Yannick Nezet–Seguin, Met’s French-Canadian musical director, said that the color of the language is more rooted than what we do in French. French consonants can be very expressive. They can be elongated more. They can also be shortened. You can make them explode faster or slower. This changes the perception that listeners will get when they hear a Verdi great melody. It’s important to note that consonants in Italian are very important, but vowel is more important.

Verdi’s second Paris commission, “Don Carlos”, was Verdi’s second after “Les vepres siciliennes” (1855). It adhered to the great opera form Parisians required: five acts including a ballet. The Met’s adaptation of “Don Carlos” uses Joseph Mery’s original libretto and Camille du Locle’s adaptation. It includes elements from Friedrich Schiller’s “Don Carlos”, as well as a first act set in Fontainebleau forest, and a third act that burns heretics. Based on Eugene Cormon’s “Philippe II Roi d’Espagne”, the Met’s adaptation.

Many elements from the original have been restored by The Met.

Six singers of superior quality are required: a soprano (Sonya Yancheva), mezzosoprano(Jamie Barton), alto (Matthew Polenzani), tenor [Matthew Polenzani], tenor (“Matthew Polenzani”), baritone (Etienne dupuis) as well as two basses (Eric Owens & John Relyea).

This family drama is worthy of a Netflix series. Carlos, Prince of Asturias is engaged to France’s Elisabeth de Valois. However, the Peace of Cateau-Cambresis required Elisabeth and Philippe of Spain to marry each other. Philippe has an affair with Princess Eboli. Carlos confronts his father with his sword while defending the Flemish. Rodrigue takes the side of the king and forces his friend to give up his weapon. The king is caught between his own power, and the Catholic Church’s, which is ruled by a blind, 90-year-old grand inquisitor.

Verdi’s longest opera, “Don Carlos”, runs for more than five hours without intermissions. According to Andrew Porter’s research, which cited L’Art Musical and La Gazzetta Musicale di Milano, the rehearsal on February 24, 1867 included 3 hours, 47 mins of music that lasted until 12:23 a.m. The music was cut by 19 minutes by the run-through of March 9, 1867.

After the discoveries of Rosen and Porter, Ricordi published Ursula Gunther’s 1974 complete vocal-piano edition. It included versions that were rehearsed in 1866, 1867, the premiere performance on March 11, 1867 and the second performance two hours later.

Gabriel Dotto will edit the University of Chicago Press’s 31 volume Verdi Critical Edition’s Don Carlos. It will likely contain a Paris score as well as Italian editions of four and five acts (Milan 1883), respectively. Dotto stated that his job is to determine which cuts were made at Verdi’s request and which “were instead imposed for completely pragmatic reasons.”

The Met used 1866 and 1867 rehearsal materials as well as opening night to source material. They interwoven them with the marked-up parts that many of the orchestra had used during the 2015 revival in passages similar to the four-act Italian.

Wendy Skoczen (Met’s chief librarian) said via email that many operas are puzzles. This is a difficult work in the standard repertoire, especially for Verdi.

Jessica Phillips, acting principal clarinet, can find it confusing to hear French lyrics in her music while Italian words are being used.

She said, “It’s very distinct, especially for wind players.” “The vowels are longer and French consonants are more frequently repeated.

February 14th, orchestra rehearsals began. Nezet-Seguin cut a 16th note here and a eighth note there while he sang the vocals. This included the Celestial Voice that ended the auto-dafe. The conductor pointed out that Eboli’s “O don Fatal” was not possible without the “bub bub bub bub” of the trumpets to principal bassoon William Short.

Nezet-Seguin made a joke about the adjustment made during the Posa’s death, saying: “It wasn’t really clear in the score so I made an executive decision. Giuseppe will hear me one day.”

Dupuis did Rodrigo in Italian in Berlin in December. He has to battle muscle memory when phrases begin on different beats. Notes are elongated. Words are reversed in translation. Pronunciation is altered such as “sire”.

He said, “Accidents do still happen.”

The ending of the Carlos-Elisabeth duo, which was sung in a semitone less in the 1867 French, is an example of this transformed mood.

“It’s calmer. Dupuis stated that she is going to the convent, while he will fight the war. “Whereas it’s not in the Italian, it feels as if they’re ripping each others’ hearts out.”

The Met drops the opening woodcutters, one of the sections that Verdi had cut to reduce run time. Also dropped is the ballet La Peregrina. It also includes Rodrigue’s second act duet with Carlos, as well as the fourth-act scene between Elisabeth, Eboli and Le Comte de Lerme. The fifth act’s finale features a quieter version than the 1884 revision. This is intended for the November Italian revival.

Nezet Seguin hopes to revive a French staging of Stefan Herheim’s Covent Garden, “Vepres” performance. He was moved by the “Don Carlos” rehearsal.

He said that he heard it all and felt there was more fluidity in French.