This original piece from Thunder Dash is fantastic and has an amazing story behind it. I'll let Thunder Dash explain in his own words:
"So one day I was on MLPForums, roleplaying with this guy. Little did I know that he was in the military. So, as we were roleplaying, he sent me a personal message. He told me that he was in the US Army... He wanted a song that kept him and his guys motivated. So, I wrote this song both in honor of Rainbow Dash and our soldiers fighting for our country. It was also the holidays, so you could say it was also an early Christmas gift. It was an honor for me to write this song for him!"
Give the song a listen! Thanks to Thunder Dash and to all the great fans out there using their talents in many ways.