This is a curious word, meaning best dress. Its first use was in 1896, so I guess it was known in the time of the music that is presented here. The tracks here are mostly ragtime, so maybe what is meant is also that: ragtime that is happy. Happy or not, I felt a bit disappointed. The sisters Labèque have done better works.
I wrote earlier about this precursor of jazz. Its influence on both jazz and classical music cannot be understated. I’ve tried many times to like it, but never succeeded. This nervous sounding music never touched me.