1800-1900. Edison invented the cylinder recording machine in 1878, but I believe most of the earliest recordings were of classical music or speech. A man named Fewkes showed ethnologists and other scientists the use of wax cylinder recordings in their studies; material on American Indians was collected from 1890 on.
I am not familiar with when cylinder recording of popular music became important, but I doubt that much was done before 1900. Not until then can the method be said to have "revolutionized" popular music. Sheet music continued to be popular. I wonder if anyone has done a thesis on the increasing use of recordings and the gradual decrease in sheet music and the piano, etc., in the average middle class home. (Dull stuff, but adds to our knowledge of popular culture)