In his debut as Frost’s new conductor of the Frost Symphony Orchestra, Gerard Schwarz offers a varied and demanding program. It includes the suite from the ballet Estancia by Alberto Ginastera, one of the greatest 20th century composers of the Americas; Samuel Jones’s Tuba Concerto, which Schwarz has called “the finest solo work for that instrument ever produced,” featuring Frost faculty tubist Aaron Tindall, and the evening closes with Brahms’s magnificent and melodic Symphony No. 2.