The avant-garde ain’t what it used to be. I was in Washington to see the spectacular Dada show at the National Gallery (it will move to the Museum of Modern Art on June 18) and was stunned by the inventiveness, the cheek, the passion of the satire, the way anti-art became the art of the future (pop art, conceptual art, even “language” poetry). Our contemporary avant-garde doesn’t seem even to have begun catching up with what artists, poets, and musicians were doing in Switzerland, Germany, France, and New York between 1915 and 1922. One surprise treat took place in the lobby of the East Wing, just outside the entrance to the show. Sixteen Gulbranson baby-grand player pianos, four bass drums, three xylophones, three fans (with plastic interfering “fingers” that rattle like cards in bicycle spokes), a gong, a siren, and a brace of bells were waiting to be triggered by Boston’s Paul D. Lehrman, who was manning a computer for a 10-minute excerpt of American composer George Antheil’s Ballet mécanique — music that he created in 1924 to accompany a film by Fernand Léger but that was far too complicated to be executed before the age of electronic synchronization.

In 2001, Lehrman joined forces with Gil Rose and the Boston Modern Orchestra Project for a live performance of Ballet mécanique at Symphony Hall (with only 12 player pianos), and just last year, Image Entertainment released Lehrman’s dazzlingly edited version of Antheil’s score (which was longer than Léger’s film) as part of an extraordinary seven-DVD collection, Unseen Cinema: Early American Avant-Garde Film 1893-1941. An essay by Lehrman appears in an anthology with the same title that is unfortunately not included with the DVDs. The crowd in the lobby and on the stairwells of the National Gallery (the best view of the pianos and xylophones is from above) were grooving to the percussive Stravinskian rhythms of this impetuous, hilarious, exhilarating, colorful, chilling score — an ironic hymn to the industrial world and its accomplishments (and its menace). Performances continue daily at the National Gallery.

At Jordan Hall, Stephen Drury’s Callithumpian Consort gave a rare performance of Greek composer Iannis Xenakis’s 1969 Kraanerg — a 75-minute confrontation for four-channel tape and live orchestra that obviously descended from Antheil. It was like living through a war, surrounded by rapid-fire machine guns, roaring airplane engines, exploding bombs, blasting factory whistles, moaning foghorns, and chimes striking the hour, interrupted by extended pauses — the blessed relief of silence, however ominous. Heavy demands are made on the live musicians, but the instruments are skillfully deployed, and there must be considerable satisfaction in a performance of the quality Drury elicited. By a quarter of the way through, the music has become more of an ordeal than a pleasure. If you think of other pieces of similar length, like Mahler’s Fifth Symphony, you might yearn for more of Mahler’s beauty and variety. I’m grateful to have heard this, because now I never have to hear it again.

Another American avant-gardiste, but in high contrast to Xenakis and Antheil, Virgil Thomson wrote some of the most deceptively simple and appealing music of the 20th century. One of his masterpieces is his first operatic collaboration with Gertrude Stein, the fanciful and charmingly non-linear depiction of spirituality, Four Saints in Three Acts (1934). The best version I’ve ever seen is the one Mark Morris did five years ago. With its indirect but evocative language (“Pigeons on the grass alas”) and absurdist devices (there are more than three acts, and they’re not performed in numerical order), it’s a work people find hard to follow. Morris revived it last week at the Brooklyn Academy of Music as the first half of a double bill with another masterpiece, also out of commission for some years, Dido and Aeneas, in which he originally choreographed the dual role of Dido and her nemesis, a sorceress, for himself.

Both works got shapely and moving musical performances under the baton of Baroque-tenor-turned-conductor, Jeffrey Thomas, with several Boston-based singers in excellent form. Baritone James Maddalena’s Aeneas was the most moving and vocally beautiful performance of that role I’ve heard; he was also profoundly expressive as Thomson’s St. Ignatius (whose “Pigeons on the grass alas” became a meditation on the Holy Spirit). Soprano Jayne West was in radiant voice, and so was Baroque star Christine Brandes (as St. Theresa and Dido’s sister Belinda). Mezzo-soprano Beth Clayton’s well-sung but bland Dido, despite having one of the great tragic arias in all of opera, paled beside Maddalena’s full-hearted emotional commitment. (Morris’s first Didos were Lorraine Hunt Lieberson and Mary Westbrook Geha.) On stage, in the Thomson, Morris’s dancers flirted a little too much with the audience; the piece works best when the performers are dead serious about everything, even the jokes. And in Dido, Morris’s decision to divide his dual role between two dancers diminished the size, impact, and meaning of his original conception.