How to Read Music explains the fundamentals of reading music. Watching the video won't turn students into composers over night, but it provides a good start.
TED-Ed offers a lot of interesting and useful video lessons for students. Many of the videos are organized into playlists. Unfortunately, I couldn't find a playlist of all of the TED-Ed lessons about music. To remedy that problem, I made a playlist of my own featuring eight TED-Ed lessons about music.