Plainsong and Medieval Music Society

The Plainsong and Medieval Music Society (PMMS), also spelled as the Plainsong and Mediæval Music Society, is an English music society. Founded in 1888, the PMMS primarily researches, promotes and produces publications on medieval music, particularly the liturgical chant from that time to the present.

Source: Wikipedia — Plainsong and Medieval Music Society (CC BY-SA 4.0)