Not the same person as Wilhelm Adolf Popp (his dates are 1902–1955). Perhaps a relative? Also, announcement of June 25 death appeared (in a list of 1902 musical deaths) in a publication (Monatshefte) that, I believe, appeared "on stands" before June 25 1903, so fairly sure 1902 is more accurate than 1903, though I might be mistaken in some detail of my reasoning here. - Schissel