Midway through the film, director Arthur Penn (fresh off of "Bonnie and Clyde", I believe) literally shoots the events on which the song is based, and they are if anything even more amusing on screen than on record. However, anyone expecting the film itself to reflect this tone overall is in for a surprise.
By the time Arlo (playing himself) has his litter-inspired run-in with the draft board (which is, again, hilarious) we have come to know him as one of a commune-like group of people in Stockbridge which is more or less centered around Alice and Ray. The two live unconventionally with their friends in an unused Church. Alice seeks to add some stability to her life by opening a restaurant, which she does successfully with the help of friend Arlo's jingle. She and Arlo are the only members of their group who look beyond the aimless lifestyle of the members of their commune, who are content to meander through life riding motorcycles and getting stoned. We see Alice affected by the drug-inspired struggle and death of addict Shelley and Arlo affected by the long illness and eventual death of his father, Woody Guthrie. Perhaps their emotional connections to their lost loved ones are what clue them in to the shallowness of the lives around them. But if Arlo has his music to move on to, Alice is fairly glued to her life with the stoned-out Ray, their friends and her restaurant. It is with great sadness indeed that she watches Arlo ride off to resume his life on the road.
The point made about the trappings of the Hippie lifestyle being so unfulfilling are well ahead of their time when juxtaposed with other movies of the era and are actually quite haunting. The problem is that they make the wonderful recapping of the events surrounding Arlo's writing of the song seem out of place. This shift in tone is never quite reconciled by director Penn, rendering the film more of a curiosity than a success.
In addition to the now-fabled Thanksgiving sequence, highlights include James Broderick's lively performance as Ray, Pat Quinn's understated one as Alice and Guthrie's ever present charm and humor. It is also a wonderful bonus to see Arlo perform his father's "Pastures of Plenty" and "Car Song" with the wonderful Pete Seeger. (That's folk music producer Harold Leventhal as Woody's manager.) The film itself is ultimately as ramshackle as the group whose story it tells, but if the era means anything to you you will find it worth watching.