I came into music in the late 60s, but we, in Australia, did not hear a lot of Country Joe and the Fish, apart from the famous "Fixin' To Die Rage", which featured on Woodstock. I had a look at the lyrics and it seems to be very much written in "in language". I think it is a love song, but with a sting in the tail. ON an Amazon review of the song, it is described as: "the bluesy free love saga" and I would go along with that. Country Joe was a proponent of the hippie lifestyle, free love and plenty of drugs. another review on the same site points to the organ playing on the song as "creating a hallucinogenic atmosphere". A third reviewer says: "Not So Sweet Martha Lorraine" is another oft-cited gem, with clever lyrics that pychedelicize ordinary romantic platitudes,..." Still another describes: the lyrically evocative country-rock of "Not So Sweet Martha Lorraine" While not being able to tell you exactly line by line what it means, I think this review sums it up: "Not So Sweet Martha Lorraine" presents four verses, with chorus and bridges, about a femme fatale figure. I wish I could quote it at length, but there are copyright restrictions, and plus, where would I start and end, it being too organic to slice and dice. Darkly poetic. Hope that helps. Don't go into it too deeply. I don't think it was meant to be analysed, just experienced. It was the late 60s after all and as they say "If you can remember the 60s, you weren't there."