I'd have to go along with Martin on this one. Individual songs like Rock Island Line (I seriously doubt that it primarily sold to 12 year old girls) jolted the musical landscape, as did Wimoweh by the Weavers a few years earlier. But for albums? The only other artist I could argue in favor of would be Bob Dylan's first album. Whether one or the other album was most influential probably is more dependent on how old you were when they came out than anything else. The other key album that introduced me to folk music (which was certainly not widely enough purchased to be "most influential" was Bob Ginson's I Come For To Sing. While Gibson was far more respected in the folk community, the album cover looked as college-oriented, cool white-kid as any Kingston Trio album.

Jerry