Tumbledown is Scott Swan and Alan Collins, with Scott's son Jonathon Swan being a late arrival to the project. Scott plays acoustic and electric rhythm and lead guitars, bass and congas. Alan plays acoustic and electric rhythm guitars, as well as miscellaneous percussion instruments. Jonathon also plays acoustic rhythm guitars on most tracks, and acoustic lead guitar on “Comfort Me,” a song that Jonathon wrote. Scott and Alan also sing lead and backing vocals. Additional musicians include Jacob Smith on the drums; Stephen Collins & Nathaniel Collins on keyboards; and Kaitlyn Hall, Kay Sue Collins, Tamara Collins & Megan Collins on backing vocals.