When Italian musicians began to appear more frequently, along with new dances like the waltz and polka and a new hybrid accordion, a conflict arose, and Italian and Auvergnat musicians became segregated.
By the end of the war, there were three kinds of bals-musette:
The French upper-class began frequenting these establishments, looking for excitement among the poor and downtrodden. Some staged mock police raids for their benefit.
New musical forms like jazz and tango left their mark on bal-musette following the war, and dances like the waltz, mazurka, pasodoble, beguine, foxtrot and java spread through Paris. Later, new instruments were added, including the banjo, clarinet, trumpet, saxophone, mandolin and bandoneon.
It was in about 1945 that musette became the most popular kind of French music. Its biggest stars were known across the country until about 1960, when its popularity declined drastically. Now, a form of modern musette is emerging, and a revival of such balls is witnessed especially in big towns.