Thomas. The vast majority were aimed at the ethnic market. Certainly anything pre-world war two would have been published solely with the ethnic market in mind.

BTW., It's interesting to note that the record companies were processing ethnic discs long before they became aware that there was a market for America's own ethnic music - Ie., blues, jazz, country music etc. The reasons are fairly obvious. European ethnic groups were often concentrated in northern cities, where the record companies were. Also, American record company executives were often of immigrant stock themselves. So they knew exactly what their people wanted, and they provided it.

In any event, all this has set me wondering. We know that the pre-war ethnic record market was satisfied by large record companies, EG., Victor and Columbia. So too was the market for blues and country music. However, after the war, the majors largely gave up on those two idioms, and the market for blues and country was satisfied mainly by small local companies. EG., Trumpet and whatever the name of Jay Miller's company was called.

Could something similar have happened with the ethnic market? Could it be that the demand for polka music or czardas, or whatever, was satisfied by local record companies lodged in the Immigrant ghettos, and selling mainly in local record stores, market stalls or wherever?

I honestly don't know, but perhaps someone else would care to comment.