I'm a huge fan of Sesame Street. Watched it as a kid and absolutely loved the music in it, in the earlier (pre-90's) episodes anyway. In the late 60's they had a series of animations which are sometimes referred to as the "jazz numbers" and I have a few of them in my YouTube favorites because the music is superb, even though the audio quality is crappy. When you look at the crap music they feed kids on TV these days it's wonderful to think that they were exposing kids to these kinds of sounds back then. The whole thing is just fabulously trippy and psychedelic. The music here is by jazz pianist Danny Zeitlin who is still going strong and gigging around New York. And you have Grace Slick on vocals, how cool is that? 
 

 
My second favorite Sesame Street tune is the Indian 1-20 count, what a lovely tune. Here it is in both English and Spanish. Boy they really put a lot of artistry into kid's TV back then. 
 

 
And who can forget the infamous pinball music, they'd never write anything this good for kids now. Vocals by the Pointer Sisters! 
 

 
 

https://www.youtube.com/watch?v=wHRy-kpT8kA