If there's anything opera fans love more than onstage drama, it's backstage drama — and last week, West Bay Opera had a doozie. A week before opening night, the singer who was supposed to play the title role in Mozart's "Don Giovanni" came down with pneumonia.

After a few harried calls and referrals, they located a replacement, John Allen Nelson, giving a recital in Baltimore. Nelson, who had performed the role a few times before, was soon on a flight to the West Coast, reviewing PDFs of the Giovanni score. After three entire rehearsals, he was ready to hit the stage.

The good news is, sometimes a replacement does a pretty amazing job (just ask Brock Purdy). From note one, it was apparent that Nelson possesses a baritone as smooth as liquid silver, and the proper mixture of charisma and child-like glee to portray one of opera's favorite bad boys. Also, in the opening sword fight, he succeeded in not actually stabbing anyone, which is important.

The even better news is, the rest of West Bay's cast offers an excellent and intriguing buffet of voices, beginning with Leporello, Giovanni's servant. Antonio Azpiri's baritone is a little earthier than Nelson's, which makes a fine complement in their many scenes together. He also projects a nebbishy put-upon quality that serves whenever his boss throws him under the bus. Azpiri's performance of the famed List Aria — a statistical rundown of Giovanni's thousands of conquests — is funny and magnificent.

Playing Donna Elvira, the dumped woman who will not go away, Shaina Martinez deploys a forceful, agile soprano that befits Elvira's vows of vengeance. She does a lovely job with the final-act aria, "Mi tradi," in which Elvira describes the anguish of loving and hating at the same time. She also makes the most of Elvira's timely "blocking" entrances, arriving just in time to warn off Giovanni's latest target.

The most delicious singing comes from Michelle Drever as Donna Anna, whose father falls to Giovanni's sword in the opening scene. Drever has a powerful lyric soprano, but also the ability and taste to control her dynamics when the moment calls for it. She produces high pianissimos that seem to still the air around her. Skill and vocal intelligence came together in "Non mi dir," a justly famous aria in which Anna explains to her fiance the depths of her grief. The results are exquisite and heart-rending.

As for that fiance, Don Ottavio, Eric Levintow has a fine lyric tenor but falls prey to occasional hesitations. Ottavio is a problematic character to begin with — he stomps around declaring vendettas without really achieving anything — but he absolutely needs to believe in himself. Soprano Sarah Benzinger sometimes fails to catch the zest of the peasant bride Zerlina, but she seemed to recover with "Vedrai carino," the ultra-sweet aria in which Zerlina forgives her groom Masetto for his jealousy.

In truth, of course, Masetto was one Elvira interruption from being cuckolded. Bass-baritone Joshua Hughes plays the unlucky groom with a pugnacious, Bronxian handling of the Italian text, and uses his gangly frame to great comic effect, especially when Giovanni is beating the crap out of him.

Hughes also played Anna's slain father, The Commendatore, in a double-casting taken from Mozart-era practices. Stage director Richard Harrell also used a traditional approach to the cemetery scene, which was gratifying to see. There's really nothing creepier than a statue coming to life, but for some reason directors feel the need to mess with it. Giovanni's final descent (spoiler alert) into hell, on the other hand, is pretty high-tech, featuring a stage-height projection of the Commendatore drenched in flames (triple creepy!). Still, if they want a 100 on the test, I'm going to need a gust of smoke or a burst of flash powder as Giovanni runs into the fiery depths. Just don't burn down the theater.

The projections by Peter Crompton and Frederic O. Boulay were particularly effective, filling the stage with old-world landscapes and churches that gave the action ultra-realistic backgrounds. They included small touches of animation: flickering candles, shifting beams in God-light clouds. Callie Floor's costume designs were highlighted by Giovanni's black leather traveling clothes and Donna Anna's elegant black skirt.

José Luis Moscovich's orchestra began the overture with a few small flubs (almost like a car starting in the cold) but was perfect the rest of the afternoon. Moscovich conducted with a distinct sense of propulsion, which maintained an air of tension throughout the opera. I also enjoyed the ingenious move of placing several musicians in a two-tiered platform in the stage-right wings.

A masterful opera reveals new ideas with every viewing. This one came with Leporello's opening aria, "Voglia far il gentiluomo," which I realized resembles Figaro's "Se vuol ballare" from The Marriage of Figaro. Both arias feature servants complaining about their bosses (revolution being a constant presence in Mozart's works). In the final act, when the composer has Giovanni's house-band playing excerpts from Mozart's previous operas (and Leporello comically complaining), they include, voila! "Se vuol ballare."

West Bay Opera presents Don Giovanni, Feb. 25, 8 p.m. and Feb 26, 2 p.m. at Lucie Stern Theatre, 1305 Middlefield Road, Palo Alto. $35-$92, Proof of vaccination and masking required. wbopera.org or 650-424-9999.