Elmo and a Justin Bieber lookalike sing "Measure, Yeah, Measure," a spoof of Bieber's hit "Never Say Never."

Sesame Street are celebrating the premiere of our new sciencefilled season on Monday September 26th on PBS with this, our 1,000th video on YouTube!

If you're watching videos with your preschooler and would like to do so in a safe, childfriendly environment, please join us at http://www.sesamestreet.org

Sesame Street is a production of Sesame Workshop, a nonprofit educational organization which also produces Pinky Dinky Doo, The Electric Company, and other programs for children around the world.