The four young men in the picture are members of Beatles.
The impact of the Beatles has often been noted but cannot be overstated. The “Fab Four” from Liverpool, England, startled the ears and energized the lives of virtually all who heard them. Their arrival triggered the musical revolution of the Sixties, introducing a modern sound and viewpoint that parted ways with the world of the previous decade. The pleasurable jolt at hearing “She Loves You” and “I Want to Hold Your Hand” - given the doldrums into which rock and roll had fallen in recent years - was comparable to the collective fever induced by Presley’s “That’s All Right (Mama)” and “Heartbreak Hotel” nearly ten years earlier.
The Beatles’ music - with its simultaneous refinement (crisp harmonies, solid musicianship, canny pop instincts) and abandon (energetic singing and playing, much screaming and shaking of mop-topped locks) – ignited the latent energy of youth on both sides of the Atlantic. They helped confer self-identity upon a youthful, music-based culture that flexed its muscle in myriad ways - not just as music consumers but also as a force for political expression, social commentary and contemporary lifestyles...
To read more at http://www.rockhall.com/inductee/the-beatles
P.S. to Carl :I guess you use only Wiki to find all those information, right? I can find exactly the same picture on Wiki.