How did the beatles influence future rock and roll?

In 1962 most of the first generation of Rock n Roll artistes were no longer performing for one reason or another. (Elvis had joined the army, the Everly Brothers were having artistic disagreements, Little Richard had got religion, Buddy Holly, Richie Valens were both dead).
There was a general feeling in the music establishment that Pop Music was due to move back to being a lightweight middle-of-the road pursuit. 1960-62 - and particularly the summer of 1962, the 'summer of a thousand dances' - saw a move away from guitar bands to traditional crooners (Paul Anka, Pat Boone, Vic Dana) and to a less racially and musically diverse sort of performance.
The Beatles took Pop Music back to its roots. They directly imitated black performers (on their American tours they even shared a stage with them), they encouraged energetic involvement from their fans, and they played and wrote their own music (by 1962 most pop performers were using professional arrangers and orchestras for their accompaniment).
In short, the Beatles made Pop Music exciting, loud, guitar-based, and a young-people's music. If there had been no Beatles we would still be listening to Frank Sinatra soundalikes.