The Naughton sisters celebrate the glorious, exuberant sound of music for two pianists with a program of American compositions. John Adams’ “Short Ride in a Fast Machine” provides an explosive opening before Paul Schoenfield’s extraordinary homage to American popular music, Five Days from the Life of a Manic-Depressive, with its joyful highs and quieter contemplations. The restless, helter-skelter Sonatina by Conlon Nancarrow preludes Copland’s evocative portrait of a Mexican dance hall, “El salón Mexico,” beautifully and intimately arranged by Leonard Bernstein. And Copland’s “Variations on a Shaker Melody,” extracted from his orchestral suite Appalachian Spring, provides a gentler note to end the Naughtons’ colorful and skilfully performed love letter to their homeland.