“This Heart of Mine” was recorded by the New Grass Revival on their 1975 Flying Fish Records album Fly Through the Country. The album marked the New Grass Revival’s emergence as the central act of the newgrass movement, with Sam Bush on mandolin and lead vocal, Courtney Johnson on banjo, Curtis Burch on dobro and guitar, and Ebo Walker on bass.
The song was written by Steven Brines and Jim Smoak, from the New Grass Revival’s earliest period when the band was developing its repertoire of original progressive bluegrass material. The song’s authorship is not consistently documented in the publicly available discographic sources for this particular track. The early New Grass Revival catalogue mixed Bush originals, contributions from Curtis Burch and Courtney Johnson, and outside material in the country-rock-into-bluegrass crossover register; the Flying Fish liner notes are the firmest reference for the writer attribution.
The lyric is a heartbreak-and-yearning piece: the narrator’s heart caught between what he wants and what he knows is best for him, with the chorus repeating the “this heart of mine” phrase as the central pivot. Bush’s lead vocal — clean, slightly fragile in the upper register — carries the lyric without overplaying it. The song works as a moderate-tempo vocal piece in G or A with a clear instrumental break.
