Sweet Unknown is the debut album from Heartless Bastards front-woman, Erika Wennerstrom, and will be released March 23, 2018. NPR describes Wennerstrom's voice as "warm yet gritty, throaty yet sweet, gigantic yet intimate... a mix of country-rock twang, classic-rock heroics and restless ambition that's not afraid to incorporate psychedelia, indie rock and pure pop songcraft."