Martin E. Ressler (1922-1987) was a Lancaster Mennonite song leader, choral director, and book collector. In 1993, Ressler's collection, including nearly 4,000 hymnals, songbooks, and other church music-related books, was donated to Mennonite Life. The following catalog of titles in the Ressler Music Library records title, author, year of publication, and publisher, and is searchable.
"The collection has extensive materials on the Anabaptist groups including Mennonites, Amish, Church of the Brethren, Brethren in Christ, and others. Consequently, this collection reflects both the original German language of these groups and the English tongue which they eventually needed to use in North America. Ressler emphasized materials on Mennonites of Swiss and south German background and especially on conservative Mennonites. The majority of the collection focuses on materials published from the middle 1800s to the middle 1900s. Books published in the United States predominate, including many commercially-published hymnals of gospel songs and Sunday School songs. Official denominational hymnals of the Protestant groups are also well represented, as are oblong-format books used in singing schools of the nineteenth century. It is notable for its size and particular denominational focus rather than its international flavor or its wide sweep of time periods." (Zeager, Lloyd. "The Ressler Hymnal Collection." Pennsylvania Mennonite Heritage, April 1994.)