I saw this movie in elementary school during the early 80s. It was in color and it was in English. I remember they were wearing 70s style clothing and there was a young teenage boy that was upset about something. Two girls started singing to cheer him up and they sang a song that repeated the line “sunshine, sunshine.” It was very upbeat. He started feeling better and was also dancing around and at the end of the song he stepped in something in the kitchen. It was either dog food or dog poop. After the song they went on to solve the problem the boy was worried about.