Simplify the following text for a Grade 4 native English-speaking person.
Original: Twitty held the record for the most number one singles of any act with 55 No. 1 Billboard country hits until 2006 when George Strait broke his record .
Simplified: He held the record for the most number one singles of any act with 55 No. 1 Billboard country hits until George Strait broke the record in 2006 .