Simplify the following text for a Grade 8 native English-speaking person.
Original: The word thief in the song refers to the tumor and at the end of the song there is a sound clip of a young girl that is actually Mina Kim singing a `` Little By Little '' with Maida 's wife Chantal Kreviazuk .
Simplified: The `` thief '' mentioned in the song refers to the tumor . The short clip at the end of the song consisting of a young girl singing a Sunday school song is a real audio clip of Mina Kim singing `` Little By Little '' with Maida 's wife Chantal Kreviazuk .