A NEUTRINO original: https://www.nicovideo.jp/watch/sm37117233

Earworms:
https://www.nicovideo.jp/watch/sm37055741
https://www.nicovideo.jp/watch/sm37096684
https://www.nicovideo.jp/watch/sm37198038
https://www.nicovideo.jp/watch/sm37197489
https://www.nicovideo.jp/watch/sm37315935
https://www.nicovideo.jp/watch/sm37777064
https://www.nicovideo.jp/watch/sm36515685
https://www.nicovideo.jp/watch/sm37092723
https://www.nicovideo.jp/watch/sm37686568
https://www.nicovideo.jp/watch/sm37716686
https://www.nicovideo.jp/watch/sm37010925
https://www.nicovideo.jp/watch/sm36594334

Upbeat, to varying degrees:
https://www.nicovideo.jp/watch/sm36584139
https://www.nicovideo.jp/watch/sm36285142
https://www.nicovideo.jp/watch/sm37597218

Beautiful:
https://www.nicovideo.jp/watch/sm36967093

Wild:
https://www.nicovideo.jp/watch/sm37660330
https://www.nicovideo.jp/watch/sm37634961
https://www.nicovideo.jp/watch/sm37629565
https://www.nicovideo.jp/watch/sm37467451
https://www.nicovideo.jp/watch/sm37660489