The pair has an increasingly popular Facebook fan page and YouTube channel.
"We feel like we're bridging a little bit of the gap between the hearing and the deaf community. They get to enjoy music, just like hearing people do," said Paul Sirimarco, who co-stars in the videos.
What's even more incredible? Three weeks ago, Paul Sirimarco didn't even know how to sign. Now, he's signing the alphabet in instructional videos online.
This viral success was certainly not planned.
Sign language interpreter Tina Cleveland wanted to teach her fiance, Paul, to sign one song they could perform together at their October wedding.
They started practicing "You're the One That I Want" from the "Grease" soundtrack during a long road trip to Mammoth. Tina decided to record it.
Paul said, "Next thing I know, she says, 'Let's put it on Facebook.'"
Paul said hundreds of their friends shared the videos. Then, thousands. Now, that video has more than a million views on YouTube.
The two continued making videos. They've covered everyone from the Beatles, to Michael Jackson, to Randy Newman.
Beyonce recently shared a link to Tina's cover of "Halo" on her Facebook page.
Tina can't believe all the attention. "Like what? What is happening?" she said.
The couple said the best part has been the pictures and videos of deaf kids watching their videos.
"That feedback of, 'Thank you so much, I have not had this connection with music and now I do,' -- it's, like, wow," Tina said.
Even though both Paul and Tina have full-time jobs, they want to keep making as many videos as possible. They're now receiving thousands of requests.
They are even in talks with YouTube about utilizing free studio space to produce videos that could end up with an even larger audience.