Here’s a kind of tribute we’d like to see stateside for the sesquicentennial of Charles Ives, our towering though still far too little known and appreciated American prophet. The bill crowns the dauntless German conductor Ingo Metzmacher’s 10th and final season as artistic director of the Kunstfestspiele Herrenhausen. An inveterate explorer of undiscovered musical continents, Metzmacher has a rare talent for sharing his enthusiasms. For his Ives extravaganza, he has booked Germany’s biggest concert hall, an imposing domed rotunda inaugurated in 1914. Together with the veteran American scholar–baritone Thomas Hampson, he has curated an anthology of orchestral pieces, songs, and choral works, shot through with echoes of the 19th-century parlor songs, hymns, and marching bands that fed the composer’s uniquely multilayered, often transcendent, sometimes boyishly mischievous musical imagination. That the performance is set for the Sabbath at eleven A.M. may point to Ives’s personal history as an adolescent church organist in high demand (this was before he revolutionized the insurance business and made a killing). For true believers, and this special may convert you, the Canadian virtuoso Marc-André Hamelin offers a late-afternoon recital juxtaposing two sonatas that are alike only in being among the most original, monumental, and technically uncompromising behemoths in the solo-piano literature: Beethoven’s Hammerklavier and Ives’s Concord, its four movements paying homage to the literary, intellectual, and spiritual luminaries of that semi mythic New England town—Emerson, Hawthorne, the Alcotts, and Thoreau. —Matthew Gurewitsch