PATTI IN CINCINNATI
February 20, 1882.
Richard Ellmann in his biography Oscar Wilde (which contains one of the four previously published chronologies of the lecture tour) says that Wilde lecturing in Columbus, OH, on February 20, 1882 . This is incorrect—although Wilde was in Cincinnati on that day it was only as a stopover on his way to Louisville, KY where he lectured on the following night. Wilde returned to Cincinnati for his lecture, as he had planned to do, on February 23.
However, Wilde was not idle on this stopover visit to Cincinnati. Upon arrival he checked into the Burnet House, before driving out to the famous Rookwood Pottery, returning in the late afternoon to give an interview to The Cincinnati Enquirer. In the evening he attended the opera  as an honored guest in the director's box.
Singing that night was Adelina Patti (1843—1919) the highly acclaimed Italian opera singer (born in Spain) who was professionally known simply as Patti. She remains one of the most famous sopranos in history owing to the purity and beauty of her lyrical voice and the unmatched quality of her bel canto technique. The composer Giuseppe Verdi, writing in 1877, described her as being perhaps the finest singer who had ever lived and a "stupendous artist". Like Wilde she was a client of the theatrical impresario Richard D'Oyly Carte, and also a guest at The Burnet House in Cincinnati where Wilde stayed for his first lecture there.
The concert that Wilde attended was a closing entertainment of selected arias by leading singers from the previous week's Cincinnati Opera Festival. Madame Patti chose "Bel Raggio" from Semiramide by Rossini.
Afterwards, Wilde was taken backstage to be introduced to her—the diva must have made an impression on Wilde as he mentioned her in glowing terms his only novel The Picture of Dorian Gray (opposite).
Full concert program from the 1882 Cincinnati Opera Festival
Maria Callas, Bel raggio lusinghier - Semiramide - Rossini (You Tube)
Adelina Patti singing “The Last Rose of Summer” (1905)—in diminished quality
Cincinnati Music Hall—Then and Now
Wilde's Lecture In Cincinnati, February 1882
 Wilde actually did lecture in Columbus, OH on May 3, 1882.
 At the Great Music Hall (extant) not the Opera House where Wilde lectured two days later.
The Cincinnati Enquirer 21 February 1882, 4.
The Cincinnati Enquirer 21 February 1882, 2.
The Picture of Dorian Gray
"Dorian, you mustn't let this thing get on your nerves. You must come and dine with me, and afterwards we will look in at the opera. It is a Patti night, and everybody will be there. You can come to my sister's box. She has got some smart women with her."
"My dear Basil, how do I know?" murmured Dorian Gray, sipping some pale-yellow wine from a delicate, gold-beaded bubble of Venetian glass and looking dreadfully bored. "I was at the opera. You should have come on there. I met Lady Gwendolen, Harry's sister, for the first time. We were in her box. She is perfectly charming; and Patti sang divinely".