SummerFest’s July 21 sellout opening night gambit, titled “Piano Extravaganza,” came off with both Steinways still standing and the audience more than a little giddy, after hearing four renowned pianists play Gershwin, Ravel, Rachmaninoff, Wagner, Saint-Saens, Rossini and Bizet. Add to those four pianists and two Steinways two actively engaged page turners and a mystery guest, a youthful Barnett, either Stephen or Steven, pulled up from the audience, as if unplanned, to play a work listed as Franz Schubert’s Standchen for Piano – 6 hands. After they’d played a few bars, Anne-Marie McDermott pointed out to Jon Kimura Parker that between the two of them they had only four hands, so they searched the audience for another pianist. Later, when it was time for encores, there were more hijinks. A piece announced as “Brahms’ Symphony No. 4 arranged for three players” devolved into a mishmash of John Williams’ music from “Star Wars,” replete with Parker’s impersonation of a “Star Trek” character (Mr. Sulu, is that you?) in uniform giving the split-fingers hand signal. That provided a fitting conclusion for a high-spirited evening, which included pianist Helen Huang as well. The four traded duties on high and low parts and in high and low comedy, as in various pairings and combinations they played George Gershwin’s “An American in Paris” for Two Pianos, Maurice Ravel’s “Mother Goose” Suite for Piano 4 Hands, Sergei Rachmaninoff’s Suite No. 2 in C Minor for Two Pianos, Opus 17, the aforementioned Standchen, Rossini’s “William Tell” Overture for Two Pianos – eight hands (ladies on high parts, gents on low), Richard Wagner’s “Ride of the Valkyries” for Two Pianos – 8 hands (gents on melody and ladies on bass), and Georges Bizet’s Fantasy on Themes from “Carmen” for Two Pianos – 8 hands. Having had such a rousing good time, SummerFest audiences now get into the more serious business of music listening. Programs this week through next Wednesday include tonight’s (Aug. 13) 7:30 p.m. free “SummerFest Under the Stars” concert conducted by Artistic Director Cho-Liang Lin at in Scripps Park; followed by “Poetry and Divinity” at 3 p.m. Sunday, Aug. 16, back at Sherwood Auditorium. Sasha Cooke is featured with the Miro Quartet in performance of Ottorino Resphigi’s “Il Tramonto.” Julie Landsman, horn, and Miro perform the West Coast premiere of Gunther Schuller’s Horn Quintet; and Rev. Eleanor Ellsworth of St. James-by-the-Sea recites Franz Joseph Haydn’s “The Seven Last Words of Christ,” scored for string quartet. There’s a free composers forum from 12:30 to 2 p.m. next Thursday, Aug. 20, at the Athenaeum Music and Arts Library. It features discussions with composers Steward Copeland, Mark O’Connor and George Tsontakis, whose works are featured in coming weeks. Copeland, drummer for The Police and an award-winning film composer, appears at 7:30 that night at Sherwood with his documentary film “Everybody Stares: The Police Inside Out” followed by discussion. According to Copeland, the audience will gain some idea what it was like to be in the band. For information on these programs and the remaining concerts in SummerFest 2009, go to La Jolla Music Society’s fine website, www.lajollamusic society.org, or call (858) 459-3728.