"At its core, New Music Jukebox is based on the idea that everyone is struggling with in the music field, namely, that technology provides access to information and music in ways we have never experienced before," Mr. Kessler said in a recent interview. "But that great potential is being wrestled to the ground by intellectual-property-rights issues."

Comparable wrestling matches are going on in all fields that involve the exchange of creative work and information, notably pop music, which was made clear by the legal ruckus provoked free file-sharing Web sites

Mr. Kessler, an accomplished trombonist and a firebrand on behalf of contemporary American music, and his colleagues at the center have proven better at bringing about cooperation between publishers, recording companies and composers. Paradoxically, because the field of contemporary classical music involves vastly fewer people, products and dollars, they had an advantage of sorts. Still, their success may serve as a model to other fields of how to bridge conflicting interests.

In every case involving the inclusion of a score on Jukebox, Mr. Kessler said, "the copyright holder determines how people will access it." A particular composer or publisher might only want the score listed as a bibliographical entry with information on how to obtain it, as well as listings of past performances and reviews. Some scores will be available only in excerpted form, as an inducement for later purchase. But other scores, especially shorter works, will be available complete. For larger chamber works, interested users must still rent individual parts to perform them, and pay appropriate fees to Ascap and B.M.I. (Broadcast Music Inc.), the organizations that regulate the performances and broadcast of music. Yet another step down an inexorable path.