Pat Monahan of Train

Pat Monahan of Train

Courtesy of Sister/Smule

Calling all Train fans: turn on your TVs. 

It's a big day for mobile developer Smule as it debuts its first national broadcast ad for its popular Sing! Karaoke app. The ad spot centers around the San Francisco pop band's "Play That Song," itself an adaptation of Hoagie Carmichael's "Heart and Soul," bearer of one of the most recognizable melodies ever.

Train frontman Pat Monahan appears in the 15 and 30-second spots, which also feature several familiar Smule community members singing the tune on their phones in various locales (diner, bathroom, car) before Monahan joins in. The ad, which airs today during the singer's visit to CBS' The Talk, will be running on various cable outlets including MTV, VH1, Fuse, CMT, A&E and Revolt TV, among others.

"Through the familiar melody of Train's 'Play That Song,' this campaign brings to life our mission of going beyond the passive experience of just listening to music," said Kevin Carson, VP of global artist and industry relations at Smule. "We focus on connecting people through music, and our apps inspire Smule users to engage and interact with their favorite songs and artists."

Watch the ad spot below:

That effort to move listeners beyond passive listening and into participating in music creation -- sometimes with an artist's help -- is Smule's modus operandi. Sing! Karaoke, for example, lets users collaborate on tracks with singers from across the globe. More than 16 million songs are performed daily on Smule’s apps, which also includes AutoRap, Magic Piano and Guitar!. The developer is also responsible for the retired Glee App and an app that lets you sound like T-Pain. The Smule network boasts 52 million active users, up from 40 million last year, with 1.5 million paying subscribers.

Smule has partnered with several artists before inside the Sing! Karaoke app, including Shawn Mendes and Ed Sheeran, who both recently invited fans to sing along with their hits. Through May 19, Nick Jonas is inviting fans to sing "Jealous" with him and enter to meet the singer.

Coinciding with the new ad campaign, Train has signed on to be Smule’s partner artist in May, allowing members to sing alongside Monahan on the track, which reached No. 6 on Billboard's Adult Pop Songs chart and rose to No. 41 on the Hot 100. "We are always looking for creative and innovative ways to connect with our fans," he said. "Smule allows us to engage with our fans on a deeper level and we can't wait to see all the amazing duets of 'Play That Song."

Smule was founded in 2008 by Stanford PhD student Jeff Smith and Stanford assistant professor Ge Wang. Over the years, Smule has raised over $90 million over nine rounds of funding, including $22 million in series G last summer, according to CrunchBase.