Simplify the following text for a Grade 10 native English-speaking person.
Original: The album sold very well , mainly because of the success of its single , `` Swing Life Away '' , which reached number 12 on the Billboard Modern Rock Tracks , making it the band 's highest-ranking single at the time .
Simplified: The album sold very well , mainly due to the success of its single , `` Swing Life Away '' , which reached # 12 on the Billboard Modern Rock Tracks , making it the band 's highest-charting single at the time .