Let's start from the dates. No magic happened in February 1964. It started happening in England at least two years earlier, and exploded there in 1963 with numerous bands, none of which you can accuse of being influenced by the Beatles, if only because those outside of Liverpool never heard of them, but they had certainly heard the same American influences, which the mainstream AM radio in the States did not play much, but which were played by the English broadcasts of Radio Luxembourg, and I'm talking about country and rhythm & blues records of the time, as well as rock and pop records beyond the Top 40 limit favored by the American radio. I suspect that if George Martin had decided to pick up the Hollies instead of the Beatles at the time, we'd be talking about Holliesmania, or Dave Clark Five mania. The talent was there and elsewhere. George Martin would have supplied the flutes and the strings.
Strings in rock records date back to the 1950s. As do accordions, as a matter of fact (Bill Haley had an accordionist in his band.) Concept albums? Take this:
It was enough of a concept, and a clearly articulated concept (what was the 'concept' of Sgt Pepper again?) to be understood and covered in its entirety recently by a duo that wasn't even born when the Everly Brothers recorded it in 1958:
I'm waiting for somebody to cover any of the art rock concept albums. Waiting...
To write something other than Beatles songs. They would become this OTHER band.
"Everyone knows" that Robert Fulton invented the steamship---except he didn't, John Fitch did, but Fulton popularized it and made it the first practical steam-driven ship. Out of all the rock and rollers I interviewed, not one cited the Everly Brothers as an influence on anything they did---including those that I would call more "vocal/harmony" based. Eventually in a conversation they would mention them in passing, but only after citing the Beatles 20 times.
Now, you can argue till the cows come home about who was actually "first" in anything, but based on my rather extensive research and interviewing, musicians of the mid-20th century who played rock and were known for it (as opposed to some people you can pull from a bus route and quit playing when they were 17) almost without exception cited the Beatles as their major influence, and it isn't even close with anyone else. You can say they were wrong to think that way, but you just can't argue with the fact that THEY feel that way.