Whether it be the death of one or more figures such as Robert Johnson, Elvis Presley, or Chuck Berry before they ever write or record their music; or an ASB preventing the fusion of blues, country, and/or R&B into a coherent genre we would recognize today as early rock music; say that somehow, the genre of rock and roll is, for all intents and purposes, completely butterflied. How ASB is such a premise with a PoD in the 1930s?
I'm not here to ask about some of the political ramifications of this (such as the butterfly effect on the Counterculture movement, if it even exists in this hypothetical ATL), but possibilities thrown in would be greatly appreciated.
I am, however, going to ask how music in general would develop in the absence of rock and roll. Does electronic music eventually fill in the "void" left behind? Do we even get disco? What else changes, or might change? The fifties probably stay mostly the same, I imagine, but is there anything I might be missing? Any thoughts?