An important investigation: Why is Starling Marte playing an accordion in the Pirates' clubhouse?

Step into a baseball clubhouse any day of the season, and you're bound to hear some kind of music booming from the clubhouse speaker system. Sometimes it's country, other times classic rock. Many teams cue up a celebratory hip-hop playlist after they win. You'll hear Latin music and '90s alternative playlists and the occasional throwback to Frank Sinatra.

Visitors to the Pirates' PNC Park clubhouse before Thursday's game against the Padres were greeted by the dulcet tones of ... something else entirely.

Yup, that's Starling Marte , walking around with an accordion strapped to his chest.

Why, you might ask? One of his teammates quietly theorized that Marte bought the instrument online just to joke around with it. But by the time the Pirates clubhouse closed to the media, this intrepid MLB.com correspondent was left amused, but confused.

And I couldn't figure out where/why Starling Marte got hold of an accordion. But he seemed to be having a good time. — Adam Berry (@adamdberry) August 11, 2016

Fortunately, Dan Potash of ROOT Sports got to the bottom of the story.

See, the accordion does not, in fact, belong to Marte at all. It is the property of one Felipe Rivero, the Pirates' new lefty setup man and Accordionist-In-Training. According to the Potash dispatch, Rivero has only been playing the squeezebox for a few months, taking lessons to perfect his craft. Marte, apparently, needed only a few minutes.

So he picked up the instrument and carried it around the clubhouse, serenading his teammates with a straight face and laying down an unusual backing track for manager Clint Hurdle's daily chat with the media.

Marte clearly has this baseball thing figured out pretty well. What instrument will Marte try to master next? Here's hoping it's the keytar.

Adam Berry has covered the Pirates for MLB.com since 2015. Follow him on Twitter at @adamdberry.