The staff at Coalition Drum Shop in La Crosse, Wis., knows her as "Mary."
According to WKBT in La Crosse, store manager Dustin Hackworth says the "grandma drummer" arrives every two months or so, sits down at a kit and starts wailing away.
"Every time she comes in, we think, 'Man, we should video tape this' and we finally did," Hackworth told the station.
Thursday night, the shop posted a clip on YouTube. Next thing you know, it had been viewed 100,000 or so times.
A key question remains unanswered: Who is she? WKBT is hoping to hear from someone who knows.
We kind of like the mystery, though.
Update On Saturday At 2:40 p.m. ET:
WKBT says it's identified the "grandma drummer" as Mary Hvizda of Onalaska. Hvizda tells the station that she's played in several bands since she was 16. (H/T to Two-Way reader Patrick Gerbus).