I'm no music teacher, but I have learned through my own teaching that learning how to match pitch IS possible at a young age - if it's fostered in our children. What do I mean by that? It's as simple as singing with your children. I have no pictures of our experience because my hands were a little busy, but here's something that's simple and you just have to take a couple minutes out of your time to do it.
On the way home from gymnastics one night, instead of listening to the radio or MY music on my IPOD (which I won't lie, my daughter is a master at "Hello" by the Dragonettes or "Rumour has It" by Adele) we listened to my Kids folder on my IPOD. I have hundreds of kids songs on there that never get played because the car is my place and I like to relax and NOT listen to Row, Row, Row Your Boat when I've been singing it all day at work. BUT, I turned on the music and we sang together.
I find (personal choice) that I enjoy/prefer singing with my kids in the vehicle. Sitting around at home in a circle singing together just seems to planned and "schooly". Plus, singing in the vehicle puts my inambitions aside, I can sing loud and silly and no one else will hear me. Plus the kids LOVE it! So it's a win, win, win situation.
So the next time your in the car with the kids - whether you have Kids music on the radio or not - sing with your kids. Teach them songs that YOU used to sing as a kid. Singing with them only makes them more confident in their singing ability. And who doesn't want to provide their kids with confidence?