How could I use the computer to teach my kids how to play piano or guitar?

Episode 980 (2:18:17)

Mike from Los Angeles, CA

Mike would like to use a computer or tablet to teach his kids to play musical instruments. He tried GarageBand on the iPad, and his kids found it boring. Leo says that the iPad GarageBand app is the best option on the market. The sad part is that Apple was planning to have popular artists do video lessons, but dropped that after just a few lessons.

There are a few sites that the chatroom pointed out:

These sites may be a better, more interactive way to teach kids music.