Tonight marks one of the biggest rallies on the Bernie Sanders campaign trail, as the Vermont Senator will appear at Safeco Field in Seattle, WA to speak in front of 50,000+ people. With the Washington primary held tomorrow, the Sanders campaign is certainly eager to capture some momentum for his bid to the presidency.

Today, we’ve learned that, prior to Sanders’ speech, the beloved jamgrass group Greensky Bluegrass will perform at Safeco. The band is scheduled to perform at The Showbox in Seattle tonight, but their stop at Safeco will certainly come before quite the enormous crowd. What an opportunity!

A reliable source confirmed that GSBG and John Popper are both slated to perform, and Dave Matthews is also rumored to be in attendance for the performance. The connection was apparently made by some members of the band’s fan group, Camp Greensky, who are also active in the Sanders campaign. According to the report, Greensky will hit the stage at roughly 5:50 PM PT, while Sanders will speak some time after 7 PM PT.

There is a live stream of the rally, though it is unclear whether the performances will be included in the stream. You can watch below: