WASHINGTON (WUSA) - Until now, Eric Westendorf was known as the principal of 4th-8th grade at E.L. Haynes Public Charter School in Petworth who greeted kids and parents every morning with an elbow bump. 

Now his appearance riding an exercise bike while singing falsetto in a music video fellow teachers wrote, performed and produced for their students has put him on a new level of "coolness."   

The song is called CASRock and it's sung to the same background music in the popular hit Bed Rock by Young Money.  The teachers' version designed to motivate kids for DC's version of standardized achievement tests has gone viral on youtube.

"We wanted a way to hype the kids up before the CAS (Comprehensive Assessment Systems)," said Brigham Kiplinger, a 5th grade English teacher.  "So we took the hottest song on the radio write now and rewrote the lyrics to make them test worthy." 

"I hadn't heard of the song yet so I quickly went home and watched it on youtube," said Westendorf, who was asked by his teachers to participate one week before the actual recording.

Teachers spent more than a week after hours matching the proper syllables with the right lyrics until they had an entire song.  They recorded it after school during a "jam session," as Kiplinger puts it, and then used flip cameras to record their lip sync and dance moves for the music video.

"The kids were in P.E. class so we had to do it in two takes," he said.  "None of us had ever recorded a music video." 

Fifth grade teacher Alyssa Van Duyn has since been told by kids she could "drop a line."

"We kept it really secret the whole week we were working on it and then we had a Friday assembly for the whole school to get them pumped about taking the text the following week," she said.  "The last thing we did was show them the video and they just went nuts, they went crazy.  They thought it was hilarious."

By Monday, students had watched it on youtube so much over the weekend that they had Van Duyn's lines memorized and performed her part for her when school began.

"Kids are lyrical sponges so they've memorized the lyrics in three listens," said Kiplinger.  

They're using that gift children have to their advantage.  Many of the lyrics review the testing strategy they hope kids will remember for the rest of their lives.

"We thought about things we'd been teaching kids in the lessons," said Van Duyn.  "Things like if you see a fiction passage, these are the steps.  And the rest is motivation.  There are some kids who have been having a hard time with the tests.  You just hum a part of the tune and they're right back at it."

"We rap about what do do when you come to a math problem or a hard word in a test passage," said Kiplinger. "So it's a combination of academic and motivational."

During a time when teachers typically compete with technology to command the attention of their students, teachers at Petworth say they've become accustomed to using it to their advantage. 

Fifth grade teacher Nate Franz who came up with the rap idea captivates his classes before school starts with youtube clips of his newborn baby winking or other funny Seinfeld type moments.  The shared experience seems to keep kids happy in the classroom and more ready to learn.

"We've got kids now before they take the tests standing before their promethium boards watching it on youtube and doing all the lyrics and doing the dances much better than we do it," said Westendorf, adding that he is now considering doing a rap song per quarter. "Maybe we need to make a music video summarize all the units we learned each quarter."