Just a quick note here. Its something like 2k+ bands that are on MS but not MA. Some of these are just spelling mistakes and I don’t care enough to go through the whole list, but its probably somewhat close. After looking through a random assortment to test, its probably a good guess. Probably. A lot of these are going to be either not metal, core bands, or other non-MA kosher bands.
I had thought perhaps I was on to something with similar artists and that I would find that all of the bands in MA that had similar artists listed would be bands on MS and thus MS has mostly more popular bands. BUT, that’s not the case. Only about half of the bands in MS show up on the MA SA list.