I came upon a fascinating webpage a few days ago which contains a comprehensive listing of 'who studied with whom' within the Old Italian School of Singing. You see, I was endeavoring to find more information on Lilli Lehmann's mother, who was Maria Theresia Löw, and the latter's teacher, who was Heinrich Anton Föppel. I was able to do just that and got more than I bargained for! In any case, the list is extensive. Compiled by Heldenbariton Maximillian Hörberg, who traces his vocal lineage to Manuel García and Jean de Reszke, you can find it here. Of course, the reader may wonder if the list is accurate. My take? I believe it to be definitive even though weighted towards the Germanic spectrum. Hörberg's list is unusual, and highly interesting if only because it gives the reader a basis for tracing pedagogical thought and practice. In short: It's a vocal pedagogy nerd's delight.