A documentary about two rocks bands, spanning a number of years. Brian Jonestown Massacre and the Dandy Warhols. What makes it special is the examination of the complex contrasting personalities and the ironies of success and failure.
Anton Newcombe, the main man of Brian Jonestown Massacre, is widely recognised as a musical genius not only by his colleagues, his friends and rivals the Dandy Warhols, but also by record producers and most people who have worked with him. Sadly he and his band members are also incapable of integrating with the real world. Newcombe picks fights with band members on stage or with members of the audience (getting arrested at one point for literally kicking in the head of a fan). Newcombe knows no limits  he plays between 40 and 100 different instruments, writes and produces all BJM's music, can produce enough songs to fill a whole album in a single day, has a prophet-like obsessiveness with his own musical genius, but is also a heavy drugs user, flies into rages at the slightest compromise of his own artistic integrity, orders his band members about as if they are lower forms of life, and can blow deals as fast as he makes them. BJM go through a large number of record labels in fast succession  they sign them up as soon as they realise Newcombe's talents and let them go as soon as they realise he is totally uncontrollable.
The Warhols acknowledge their debt to Newcombe's creativity and don't even put themselves in the same exalted sphere of greatness  but the Warhols have something that BJM don't  the ability to integrate their talents with common sense, the real world, and their market  as a mixing pot of talent (even if much of it is distilled from guru Newcombe) and accessibility, they are the very definition of 'cool.' DiG! follows the parallel careers of the two bands with increasing poignancy. At one point, Newcombe pulls stunts designed to generate publicity by sending apparent death threats and hate messages to the Warhols (in a box containing live ammunition and insults like a bar of soap 'to clean up their act')  only he forgets to tell them it's a stunt and they get so paranoid they take out a restraining order against Newcombe. By the time the Dandy Warhols take off in Europe with hits like 'Every Day Should Be A Holiday' and 'Bohemian Like You', Newcombe is becoming increasingly isolated. BJM are stopped and the band breaks up when they are arrested for possession of marijuana  the Warhols get busted for drugs around the same time, let off with a warning, and even allowed to keep the grass.
The wider appeal of DiG! is that the lessons of genius versus accessibility go way beyond two bands or even rock music. The downside is that it is still a documentary, however intimate, and it will mostly only appeal to dedicated film fans or people who are already interested in the music of one or both of the featured bands. Newcombe may well be a largely unrecognised genius, and there are feint glimpses of this in the film, but to the unattuned ear there is little more than the assertions of the people interviewed to attest to this. In the words of one of the band members: "In every spiritual tradition, you burn in hell for pretending to be God and not being able to back it up." Newcombe isn't pretending  but numerically there are maybe still insufficient people to appreciate him in his own lifetime, and DiG! has an uphill struggle to rectify the balance in favour of a tortured but largely unrecognised genius.

I cringed all the way through this movie. First of all, the idiotic plot has little to do with Parson's own story. Hollywood has attempted to create a kind of comedy car chase movie. Imagine "Englebert Sings Hendrix".
Do not take anything about this movie to be accurate. The name Parsons in the title and stealing of his body is just used as springboard for a low budget chase movie, a blatant attempt to grab a few bucks from the Parsons legacy and his fan base. Gram's father had long since been dead in 1973, the other global characters are fictional, none of this has anything to do with Grams life or death.
If you are a Gram fan, I advise you to not see this movie. I wish I hadn't. It's saddening to see something special be treated as such disgracing fodder. I'd swear I could hear Gram turning in his grave while the movie was playing. If you are not familiar with Gram's life and legacy, do not take anything in this movie as being representative of Gram.
I cannot say enough bad things about this movie. If Gram were alive and saw this movie, he would kill himself. Then again, maybe he'd be afraid to if he knew this movie were to result.