Eight Melodies is Ninten's Final Smash in SSBTUF. Ninten calls Ana, Lloyd and Teddy. The four start singing the eight melodies from Mother. The enemies start to cry because of the beautiful music, then Ninten is free to attack enemies for 10 seconds while his friends continue singing.
This comes from the final fight in Mother. During the game, Ninten learns eight melodies. He and his friends can't defeat Gyigas, so they start singing the eight melodies. Giygas then flees because of emotional stress, but promisses to return. He actually returns in Earthbound, and Ness and friends defeat him once and for all.