Suiheisen no Uta

Obayashi Kenji lost his family in an earthquake and now works as a taxi driver. One night, a girl hums a melody in his taxi that reminds him of his wife and child. As he searches for the song, Obayashi discovers his wife's feelings through it. With the help of the girl and her musical friends, they create a small miracle in the town. (Source: Japanese = NHK || Translation = MyDramaList)