William Kinderman, a musicology professor at the University of Illinois at Urbana-Champaign, has been busy reconstructing the first movement of an unfinished—and largely unknown—piano trio by Beethoven, according to an article in the current issue of the Journal of Musicology Research.

Mr. Kinderman has worked from surviving sketches for the trio that appear in a manuscript known as the Scheide Sketchbook, now in private hands in Princeton, N.J., as well as with a draft of the opening movement in a Berlin library. He has reassembled enough of the movement to make a brief recording (available online for PC or Macintosh). Alas, he tells the university’s news bureau, “the source materials extant for other movements are much more limited.”

Beethoven started the trio in 1816, when he was also at work on several other pieces that he did not finish, along with some that he completed, Mr. Kinderman says. The composer was also tinkering with parts of what became his famous Ninth Symphony. The journal article looks at the trio, the sketches for it, and the Scheide Sketchbook in the context of what Mr. Kinderman says was a pivotal phase of Beethoven’s career.