Honestly, finding a song for Starflight was very, very tough, considering that he has to sound sad and nervous and yet heroic at the same time.

And lo and behold, from the good old Disney song collections, I found one. Starflight's theme is sad and nervous, like he's losing something he once loved, but at the same time, one who wants to take a stand against the evil around him. He knows that it's what he's gotta do, and he needs to give it all he's got this time.

Song: Spencer Lee "Still I Fly" (from Disney's Planes: Fire and Rescue)

https://youtu.be/D7V12y7FHPQ