Sentence 1: Rex had always wanted to learn to play an instrument. 
 Sentence 3: At first it was tough to play 
 Sentence 4:  However, he practiced until he felt comfortable with the violin 
 Sentence 5:  He was happy to finally be learning how to play an instrument 
 Option 1: He decided to learn to play guitar. 
 Option 2: He decided to learn to play violin.