Task: Story Composition
Input (English): Premise: Rex had always wanted to learn to play an instrument. 
 Initial Context: He decided to learn to play violin. 
 Original Ending: At first it was tough to play. However, he practiced until he felt comfortable with the violin. He was happy to finally be learning how to play an instrument. 
 New ending: At first it was tough to play. However, he practiced until he felt comfortable with the guitar. He was happy to finally be learning how to play an instrument. 
Output (English): He decided to learn to play guitar.