The songs from MLP:FiM are awesome, obviously. But the background music doesn't always get the same love, and it is awesome, too. One of the (many) great pieces of background music is the tune that plays when Rainbow Dash achieves the legendary sonic rainboom.
Thunder Dash shared some great sheet music for the sonic rainboom soundtrack. It's a fantastic resource for a fantastic bit of music. Go take a look!
Many thanks to Thunder Dash!