Recent Researches in Music Online (RRIMO) is available for use through May 31, 2020 due to the COVID-19 crisis.
Description from the publisher:
A-R Editions has published Recent Researches in Music—critical performing editions of music in seven series (Medieval, Renaissance, Baroque, Classical, 19th/20th centuries, American, and Oral Traditions)—since its inception in 1962. The series fall into two basic categories: editions that span the history of Western music, and editions with ties to specific cultural milieus. Most editions in Recent Researches in Music are devoted to works by a single composer or in a single genre.