Originally from Towson, Maryland, Hart Guonjian-Pettit has firmly cemented himself as one of the most sought-after jazz and commercial freelance trumpet players in the DC, Maryland, and Virginia area. With a busy performance schedule, Hart maintains an active career balancing such jazz idioms as hard bop, bebop and traditional jazz with classical chamber and commercial engagements. As a freelance musician, Hart has worked with several agencies and organizations in DC, Maryland, and Virginia for over 10 years, maintaining one of the busiest performance schedules in the area. His group, HartGPJazz, can be heard reinvigorating the bebop and hard bop style of the 1950s and 1960s with modern musical innovations. Hart's first album as a bandleader -- Introducing HartGPJazz is currently available on all digital streaming platforms and in CD format.

Hart has performed with musicians such as Jazzmeia Horn, George Cables, Charlie Young, Terell Stafford, Warren Wolf, Sean Jones, Delfeayo Marsalis, and Tony Succar as well as many other fantastic local icons at countless venues in the DMV. In 2024, Hart performed at the Kennedy Center in Washington DC with the Smithsonian Jazz Masterworks Orchestra as a part of the Jazz Icons series with the Washington Ballet and the New York Voices, receiving critical acclaim from the Washington Post and other media critics. In 2025, he performed lead trumpet with Grammy Award-Winning salsa bandleader and percussionist Tony Succar at the Warner Theatre in Washington DC to a sold-out audience. 

Hart has studied with Chris Gekker, Chris Vadala, and Alex Norris and has completed undergraduate and graduate study at the University of Maryland, College Park (Doctor of Musical Arts, Fall 2025). As an educator, Hart has taught full-time instrumental music with Montgomery County Public Schools since 2017. He is the most-recent addition to the UMD jazz faculty, appointed as Lecturer of Trumpet in 2025, teaching applied lessons for the jazz trumpet studio.