“The Handel and Haydn Society, which claims to be America’s oldest continuously performing arts organization, turns 200 this year. Once an amateur oratorio society dedicated to performing new music — the American premieres of Verdi’s Requiem (in 1878) and Bach’s “St. Matthew Passion” (1879), among much else — alongside the old, its orchestra and chorus have been among the country’s most prominent early-music ensembles since 1986, when it moved to playing with period instruments.”