Complex sentence: Little is known of Hans Wärmling's childhood or teenage years, it is known that he was the guitar player in a rhythm and blues band called "The Jackie Fountains" that formed in 1964 and played in the Gnesta area of Sweden until 1967.
Split into simpler sentences: Little is known of Hans Wärmling's childhood or teenage years. It is known that he was the guitar player in a rhythm and blues band called "The Jackie Fountains" that formed in 1964 and played in the Gnesta area of Sweden until 1967.