A music video is a promotional video for a song or artist that usually lasts the length of the track. It is used to keep artists relevant and provide additional ways for fans to consume their music. Good music videos are memorable, engage emotions, are visually interesting, follow the song's narrative if applicable, and promote the artist. The music video for "Radioactive" by Imagine Dragons is effective because it has an engaging post-apocalyptic narrative, unique muppet creatures, promotes the band, and uses high-quality editing and CGI.