Our son likes OK Go. Individual videos can be purchased from OK Go through iTunes.
If the meaning of "WTF" concerns you, then please skip "WTF?". (What-the-fword! There is a swear word in the video.)
Here's OK Go intersecting with Sesame Street, claiming that Red, Yellow and Blue are the three primarly colors. I think it should be Reg, Green and Blue. Oh well.