After three decades as the colorful bandleader to The Tonight Show Starring Johnny Carson, master trumpeter Doc Severinsen defies nature with a relentless schedule of touring and performing into his nineties. A musical icon traces his groundbreaking career and personal trials underscoring a life of inspiration and obsession. In 2018, at the age of 90, Doc Severinsen is still going strong as he leaves home and sets off on a performance tour. At the gym, Doc demonstrates his grueling work-out routine while his trainer calls him "a freak of nature". He shares childhood memories of growing up in a small town in Oregon, and also looks back on his early marriages, including struggles with alcoholism, and his determination to find stability for his children. The film follows Doc around the country through joyful live performances as he nostalgically retraces the steps of his career from his big band beginnings to The Tonight Show. As Doc joins The Tonight Show Starring Johnny Carson, he becomes beloved by millions of American households nightly. Through archival clips and contemporary interviews, we relive thirty years of music, comedy, and friendship of America's favorite talk show. When Johnny Carson retires from The Tonight Show in 1992, Doc moves to Mexico. However, not ready to give up performing, he continues touring nonstop, even forming a new band, The San Miguel Five. Surrounded by family and doing what makes him happy, bringing joy to audiences, Doc is savoring every moment.