Philip Gossett, a musicologist whose shoe-leather detective work in musty archives and Italian villas helped bring long-lost operas back to the stage, died on Tuesday at his home in Chicago. He was 75.

Ellen T. Harris, a professor emeritus of music at the Massachusetts Institute of Technology, confirmed the death. She said he had long been treated for progressive supranuclear palsy.

Mr. Gossett made it his life’s work to recover scores that had disappeared or become messy — marred by years of bad copies, mistakes, revisions for different singers and productions, later interpolations and lost passages — and return them to something close to what their composers had intended.

He was a pioneer in the creation of scholarly critical editions of opera scores, and served as the general editor of new editions of the works of Verdi and Rossini. He had a distinguished academic career as a professor at the University of Chicago. And he became a familiar figure in rehearsal rooms around the world, sought after by top conductors, singers and opera companies working to bring his discoveries to life.