The Glimmerglass Opera series of two concerts in the Morgan Library & Museum’s fine new Gilder Lehrman Hall concluded Thursday evening with “Strange Adventures: Portraits of Gilbert and Sullivan.” Given the Morgan’s extensive Gilbert and Sullivan holdings, which include the autograph scores of “Trial by Jury,” “The Pirates of Penzance,” and “H.M.S. Pinafore,” an evening devoted to these giants of operetta was particularly apt. And it was well timed too, since the New York City Opera’s new production of “Pirates,” which originated at Glimmerglass last summer, opened the night before.

The concert was initially to have been a program of operatic parodies by the mighty duo paired with their operatic sources, an intriguing idea and especially on point in light of allusions in the “Pirates” production to the work’s operatic roots: cutouts of Rossini, Offenbach, Verdi and Wagner, for instance, appeared during the overture. The subject is fascinating, and perhaps a way could have been found to work in Gilbert’s pre-Sullivan burlesque “Dulcamara, or the Little Duck and the Big Quack,” a takeoff on Donizetti’s “L’Elisir d’Amore.” But plans changed, and what we got instead was a program of Gilbert and Sullivan excerpts laced with readings from letters and other reminiscences. Given the personalities involved, the readings were often as entertaining as the singing, and informative too.

The young Sullivan evidently played four-hand piano music with Rossini, who had a mean wit himself. On one visit, Sullivan heard the older composer playing festive music. “It’s my dog’s birthday,” he explained, “and I write a little piece for him every year.” Sullivan also paid homage to Wagner, with a pilgrimage to Bayreuth for the “Ring” cycle and “Parsifal.” After a fine lunch on the day of “Die Walküre,” he took a nap and missed the first act. “What a curious mixture of sublimity and absolutely puerile drivel are all these Wagner operas” was his overall assessment.

The Gilbert and Sullivan partnership had its ups and downs, and one of the downs was occasioned by Sullivan’s determination to write a “grand opera.” “You should write a grand opera, Sir Arthur, you would do it so well,” Queen Victoria encouraged. But Gilbert, recognizing that the librettist in such a project took a back seat to the composer, wasn’t interested.

The program appealingly involved lesser-known selections, including some from the late, less successful collaborations, “The Grand Duke” and “Utopia Limited.” From the latter came “A Tenor, All Singers Above,” a charming piece in which a tenor laments that he is too emotionally overwrought to sing. “Ivanhoe” was represented by the soprano aria “O Moon, Art Thou Clad,” an appealingly evocative piece, if not a song to make one salivate at the prospect of hearing the opera in its entirety. For those interested in parodies, there was the splendid ensemble from “Trial by Jury,” “A Nice Dilemma We Have Here,” which some have linked to the sextet from “Lucia di Lammermoor.” And a verse of “Onward Christian Soldiers” served as a nod toward Sullivan the hymn composer.

The highpoint of the concert was a guest appearance by the veteran Irish tenor Robert White, who sang “The Lost Chord,” a charming piece of Victorian schmaltz. Here it served as a kind of requiem to Gilbert, who died in 1911, aged 74, when his heart gave out while rescuing a girl from drowning. Mr. White’s professionalism could serve as a model for the five young singers who carried the bulk of the program, capable though they often proved themselves to be: Brenda Rae, soprano; Sandra Piques Eddy, mezzo-soprano; Vale Rideout, tenor; Matthew Worth, baritone; and Daniel Gross, bassbaritone. Djordje Nesic was the able pianist.