“When we examine things finely enough,” writes Gary Saul Morson, “they baffle us with ever finer distinctions.” So it is with the music of Beethoven and the circumstances surrounding its composition. As devotees of classical music prepare to celebrate the two hundred and fiftieth anniversary of the composer’s birth, they can be grateful for all that has been uncovered about his life and times and music. But they realize there is always more to see, always finer distinctions to be made.

Mark Ferraguto, a professor at Pennsylvania State University, looks through a musicological microscope at a group of works from a single year of Beethoven’s second period. Extending from 1802 to about 1815, the second period includes some of Beethoven’s most popular compositions: the “Emperor” Concerto; the Third through Eighth Symphonies; and the “Kreutzer,” “Waldstein,” and “Appassionata” Sonatas. Tied to the second period is the idea of the heroic style, which is most widely associated with the Fifth Symphony. The heroic can be traced in that work almost like a storyline from the dark, tumultuous beginning through the bright, triumphant end. By contrast, writes Ferraguto, the works of 1806 “seem to represent a departure from the heroic idiom that characterizes Beethoven’s music of previous (and later) years.”

The virtuosic has long been associated with notions of strength and superhuman facility.

Beethoven perhaps had reason in 1806 to modulate his tone. In the spring, he suffered a commercial setback with the second run of the opera