xiipaoc's suggestion via Reddit:
I'll tell you what I want: synagogue music. There's quite a bit out there; examples are shulmusic.org and Goethe Universitat. Also, Idelsohn's books, the results of his ethnomusicological research among various Jewish groups around the world, many of which no longer exist today. Ideally these would all be tagged under both "Jewish" and "Liturgical".