The last and certainly most thrilling of this season’s personal SummerFest experiences took place Friday, Aug. 21, at Sherwood Auditorium. Historically, the annual “World Premieres: SummerFest Commissions” program attracts a younger audience as well as devotees of contemporary music. There were no vacant seats. and the works written by resident SummerFest composers George Tsontakis, Paul Schoenfield and Steward Copeland, all born between 1947 and 1952, were exceptionally accessible and well received by vociferous attendees. In a concert prelude, Schoenfield, the eldest and a former pianist, said he likes to hear the whole piece in his head before writing a new work. “Writing for me is like pulling teeth,” he said. A born storyteller and communicator, Tsontakis acknowledged that the writing process is challenging for him too, and he’d like nothing better than to stop. “But you people keep giving me commissions.” He believes that his own music has gone from prose to poetry — less is more — something rare in a society so inundated with information that music itself is getting lost. The West Coast premiere of Tsontakis’ two-part “Stimulus Package” opened the program. Scored for cello, piano and percussion, it was performed by Real Quiet, composed of Felix Fan, Andrew Russo and Davd Cossin, respectively. Tsontakis revealed that after Real Quiet’s premiere of the work at the Santa Fe Chamber Music Festival, they decided instinctively to reverse the order of its two parts. Thus, we heard the quieter “Odyssey” first and then the joyous, vitality-filled “What Papou Heard-Ison (chant tone)/Cheer Me Up” as climax. The “What Papou Heard” pays joyous homage to Tsontakis’ aged grandfather (Papou), who listened to his Juilliard-enrolled grandson’s early, atonal and arhythmical compositions; thus Tsontakis’ musical musing on what the approving old man heard in his head as he danced Zorba-like and raised a shot of Metaxa. Schoenfield’s exceptionally listenable Sonata for Violin and Piano requires virtuoso playing, which it received in its world premiere from violinist and music director Cho-Liang Lin and pianist Jon Kimura Parker. The first movement, “Vanishing Point,” is percussive, extremely American in feel, jazzy a la Joplin and rife with harmonics. Lin and Parker were perfectly matched. The third movement, “Romanza,” is a lullaby, and the fourth, “Frielach,” is redolent of gypsy violin, a Transylvanian wedding song and well-known 18th century contrapuntal techniques. The work received sustained applause. Classic in form, the sonata was co-commissioned by the Chamber Music Society of Lincoln Center and Chamber Music Northwest. The program closed with four astonishing and intricate pieces by percussionist Stewart Copeland, including the world premiere of “Retail Therapy, La Jolla.” Scored for violin, bass, bass clarinet, trumpet, drums and piano, the work is fascinating in its intricate complexity. Copeland played in all his works. He is perhaps best known as founder and drummer of The Police, a 1980s rock trio, and for his film score for Francis Ford Coppola’s “Rumblefish.” Flying drumsticks (Copeland’s), loose horsehair (violinist Kyoko Asawa’s) and palpable joie de vivre characterized the performances. The closing work, scored for multiple percussion instruments, is titled “The Gene Pool.” It proved roof raising, with red fish blue fish, Cossin and Copeland providing a fine climax to one person’s SummerFest experience, thanks to three extraordinary composers and the planning and programming of music director Lin and La Jolla Music Society president and artistic director Christopher Beach.