Jason Isbell is an American singer-songwriter from Nashville, Tennessee, best known for his work as the lead guitarist and vocalist of the alt-country band Drive By Truckers before launching a successful solo career. The 400 Unit is his backing band, featuring notable musicians like Ty Stiklorius on bass, Chad Gamble on drums, and other rotating members who support his live performances and studio recordings. Together, they have released multiple critically acclaimed albums including 'Southeastern' (2013) and 'The Nashville Sound' (2017), earning Grammy Awards and widespread recognition in Americana and alt-country circles.