Vernon - On Sunday, music-loving children at last discovered the identity of concert pianist Gail Niwa’s black mystery monster, the beast with three legs and 88 teeth, when she introduced the audience to her black Steinway grand piano. “This is my monster, and I am its tamer,” said Niwa, to the delight of the audience of children and their parents who had assembled on Sunday afternoon in the parish hall of St. Francis de Sales R. C. Church in Vernon for the Chamber Music at Great Gorge Spring Kids’ Concert. Accompanying Niwa were her brother, violinist David Niwa, and Mexican guitarist David Mozqueda. All week, Gail Niwa had been intriguing children in Sussex County schools with hints about the monster whose identity she said would be revealed at the Sunday concert. She’d even succeeded in perplexing Mozqueda, who innocently asked David Niwa, “What is this black monster we’ll see on Sunday?” In a stunning performance of Frederic Chopin’s Scherzo in C Minor, Opus 39, Gail not only tamed the Steinway, but also an audience composed of normally wriggly children - who sat still in rapt silence. “You’ll hear sounds like raindrops; you’ll see a sunrise,” Gail told the audience. “This piece has a little of everything, so let your imagination take you wherever it takes you.” Apart from the Chopin Scherzo, the program had a strongly Spanish flavor. David Niwa and David Mozqueda entranced the audience with a sensuous rendition of Argentinean 20th-century composer Astor Piazzolla’s three pieces from his “History of the Tango,” which incorporated jazzy elements, as well as extended harmonies and dissonances, with classic tango rhythms. “When we played these pieces for the school children,” David Niwa said, “we asked them to listen for similarities and differences. This composer is a guy who liked to swim with sharks, and in these pieces he reveals both the aggressive and the tender side to his character.” “Zapateado” by 19th-century Spanish violin virtuoso and composer Pablo Martín Melitón de Sarasate y Navascues was played as a duet by David Niwa on violin and Gail Niwa on piano, and David Mozqueda alternately amused and moved the audience with a soulful rendition of a Mexican folk song. The concert ended on a vibrant note with the trio performing a spirited “Danse Espagnole” (Spanish Dance) from Spanish composer Manuel de Falla, lyric drama, “La Vida Breve (Life is Short), composed in 1913. “There’s only one thing you can tell people about this wonderful concert,” said Leith Brennan, a harpist who also is a trustee of Chamber Music at Great Gorge. “You should have been here. “People don’t believe we have music as great as any people go to New York to hear. But we do, and today is more proof.”