Neil Young and Willie Nelson will perform at a concert that has been organized by opponents of the controversial Keystone XL pipeline next month. The event is set to take place on a cornfield near Neligh, NE on September 27. Tickets for the show will go on sale tomorrow.

The proposed Keystone XL pipeline would transport various forms of crude oil from Canada to refineries in the Midwest and ports along the United States’ Gulf Coast. Opponents of the project, which is already partially built, have argued that the pipeline has the potential to contaminate various aquifers, as well as damage other delicate ecosystems.

Young and Nelson last performed together in Nebraska in 1987, when they headlined a Farm Aid concert at Memorial Stadium in Lincoln.