Update
Recently, I've been making changes to the locations of very early Victor recording sessions. Victor expert John Bolig questioned why we set so many early 1900s sessions in Camden, and not Philadelphia. He reminded me of the research conducted by Allan Sutton at Mainspring Press and of the entries in the memoirs written by the Sooy brothers, Raymond and Harry, both early employees of the Victor Talking Machine Company. Harry O. Sooy's "Memoir of my Career at Victor Talking Machine Company" notes that Victor's "laboratory," as they called their recording studio in the early days, moved from Camden to Philadelphia in September 1901. He puts it at the middle of the month. I noted a gap in recording activities between Sept. 14 and Oct. 5, 1901, so we're speculating that all recordings made prior to Sept. 15 were made in Camden, New Jersey.
Raymond Sooy's "Memoirs of my Recording and Traveling Experiences for the Victor Talking Machine Company" states that they moved recording activities back to Camden the week of November 25, 1907. Our Victor data bear out Sooy's date. After Nov. 22, 1907, there are no domestic recording sessions until Dec. 9, 1907.
So, on the basis of these leads and evidence in the data, we recently changed the recording locations of nearly every pre-1908 Victor session. Still, unless we saw a specific location noted in Victor ledgers, you'll find "unconfirmed" by most place names in that era.
The capability to revisit these records makes me grateful that this is a dynamic, online project. Three of the advantages of an online, as opposed to print, reference source are: a) we are able to offer it free of charge; b) there are fewer constraints on the amount and detail of content, with no paper or printing costs; and c) our inevitable errors need not exist for all time to haunt us. Unfortunately, large reference resources such as DAHR are bound to include errors, because of inaccessible or nonexistent sources, errors in sources, and, of course, mistakes in editing. We revise DAHR entries constantly to incorporate information contributed by users, add information found in new sources, and fix our mistakes.