Singer Jesse McCartney, who was reportedly cast as Terrence in the direct-to-video animated film Tinker Bell coming this October, also ended up being the voice of Theodore in the Alvin & The Chipmunks feature film. The young artist told the Toronto Sun that he has been a huge fan of voiceover work and animation since his chipmunk experience. “When Alvin came along and Fox asked me to give it a try I was super pumped. I grew up watching the cartoon as a kid.” Loving the cartoon is one thing, but trying to reach that high-pitched voice the character Theodore has was something else altogether. “For Theodore, because he is the youngest chipmunk he has the highest voice,” McCartney says. “I have a relatively low voice. So initially when I went in there I sounded way too much like Alvin. Justin Long plays Alvin so I had to (speaks in a high squeaky tone) talk up here when I spoke and then I had to speak really slowly. So then they sped it up and I sound like Theodore.”