Brahms’s Piano Concerto No. 1 had its origin in a sonata for two pianos, written in 1854 with a slow movement that is a portrayal of Clara Schumann, composed in 1856, the year of her husband’s death. The massive concerto itself is of symphonic dimensions, as remarkable as it is demanding on a performer. Robert Schumann wrote his Introduction and Allegro in 1853, a year in which anxieties about his health and disputes with his employers, the civic authorities in Düsseldorf, were omens of his coming mental breakdown. The new work combines the form of sonata and concerto in an effective single movement, the product of a final period of creativity.