For Summer Sun Celebration, Celestia wanted to do something diferent for the celebration.
Luna recommended to Celestia for giving a look to a strange pony that wanted to do something great in Ponyville! A music festival!

Rated Teen because: massive amount of swearing

After Tank died, Rainbow Dash started to wrote a poem/diary, describing every single detail and feeling that she had, and suicide is the only way that Dashie thought that would help her for find Tank.

Rated Teen because: suicide, swearing, depression

Also, for reading/dramatic reading, here you have the soundtrack