I enjoyed the Everly Brothers because my two older sisters were into music, so I got a good education of the music of the 50’s. I was 10 in 1957. My second oldest sister bought one of the first stereo record consoles for our house.
Everlys back then were one of the few acts ever to do well both at “ballads” (slow songs) AND upbeat tunes.
Usually I find acts only do well at one or the other!