After years of popularity in the alternative rock scene, Dave Grohl wanted to express the passion for heavy metal he bore since his youth. He mentioned the catalyst of the experience being during the first leg of the tour in support of the Foo Fighters album "There Is Nothing Left to Lose", with the mellower songs making him think about the heavier bands he used to listen to. Following the tour, Grohl went to his house in Alexandria, Virginia, to record some heavier songs in his home studio Studio 606 with Adam Kasper. Grohl would play with his Gibson Explorer as he watched TV with Kasper, and once he got a riff that interested him, he would bring Kasper along to the basement, recording a drum arrangement followed by bass and guitar. Each instrumental would take about 45 minutes to complete. Grohl said that he did not intend to make an album out of the recordings – "I didn’t even call them songs because they were bare instrumentals with no intention of putting vocals on them and no direction as an actual song." After four days of recording, Grohl and Kasper had done seven tracks, with Grohl making some copies out of the master tape before labeling it Probot to distinguish from the Foo Fighters' work.