Simplify the following text for a Grade 8 native English-speaking person.
Original: Paul & Paula ( Ray Hildebrand , born December 21 , 1940 ; Jill Jackson , born May 20 , 1942 ) , were a pop singing duo , best known for their 1963 million selling # 1 hit record , `` Hey Paula . ''
Simplified: Paul & Paula ( Ray Hildebrand , born December 21 , 1940 , and Jill Jackson , born May 20 , 1942 ) are a One-hit wonder group known for their song `` Hey Paula '' .