You can go further back than that. The "Rags" of one hundred years ago are almost all great for Quickstep.
Furthermore, the music of Scott Joplin and the rest is no longer under Patten protection, therefore, you can use it at will!
Some smart Dance instructor might someday start a Studio and use only music that is no longer protected.
QuickSteps, Rags, The Old American Two Steps, and many other dance musics that were once popular, are out there for the using.
If I were younger, I would consider starting a new type of dancing that would use only free music. There would be less rules, and more fun in the dancing.
My dance form would be all about playing and flirting and having a good time.
Do you think there are still people who would want to dance just for fun?