Below is a Youtube link to a recording and video I ran across several months ago.
The band named the song, the Vietnam War Song. as they say in the description, it is a Bluegrass Banjo Ballad about Family, Heritage, and Operation Frequent Wind. An American soldier from the south was deployed to South Vietnam, took his 4 string Gibson banjo with him, and just as the soldier left Vietnam, he gave his banjo to a South Vietnamese man that loved American music. Just before the fall of Saigon in 1975, the Vietnamese man was one of the several thousand Vietnamese persons evacuated out as part of that operation, and he took the banjo with him. He was transported to the USA and built a life in Wyoming, raising cattle and a family. Years later, that man gave that 4 string Gibson banjo to his granddaughter, her name is Ryn Nguyen. Ryn still plays that banjo. She is a member of the band in the recording. The lead singer of the band narrates the basic story about the banjo, Ryn and her family before the song starts.