Complex sentence: Ten were released by Sun as Elvis' first five singles between 1954 and 1955, and a year after he left for RCA he revisited the same studio to have a spontaneous informal session with Carl Perkins, Johnny Cash, and Jerry Lee Lewis.
Split into simpler sentences: Ten were released by Sun as Elvis' first five singles between 1954 and 1955. And a year after he left for RCA, he revisited the same studio to have a spontaneous informal session with Carl Perkins, Johnny Cash, and Jerry Lee Lewis.