Od januarja 2019 dalje je pri RILM Music Encyclopedias omogočen dostop do petih novih naslovov, tako da zbirka sedaj vsebuje 54 zgodovinskih in sodobnih naslovov. Novi naslovi so:
- Domingo Prat. Diccionario biográfico – bibliográfico – histórico – crítico de guitarras (instrumentos afines), guitarristas (profesores – compositores – concertistas – lahudistas – amateurs), guitarreros (luthiers) – Danzas y cantos – terminología. Buenos Aires: Romero y Fernández, 1934.
- Hortense Panum. The Stringed Instruments of the Middle Ages: Their Evolution and Development. Translated and edited by Jeffrey Pulver. London: William Reeves, [1939 or 1940].
- Sibyl Marcuse. Musical Instruments: A Comprehensive Dictionary. New York: Doubleday, 1964.
- Curt Sachs. Real-Lexikon der Musikinstrumente, zugleich ein Polyglossar für das gesamte Instrumentengebiet. New York: Dover Publications, 1964.
- Sibyl Marcuse. A Survey of Musical Instruments. New York: Harper & Row, 1975.