He directed Tommy. His adaptation of D.H. Lawrence's Women in Love is considered a classic, and in many ways, it's very psychedelic. His work covers three decades, and informed much of the way we look at visuals. Music videos would never have been anything without Sir Ken.
His films were bandied about a lot during my college years, and I made a point to see everything he did, and I came pretty close. I don't think a day goes by that I don't think about Lair of the White Worm. It probably worked its way into my DNA. He is known for his excessive and overtly sexual imagery. His films are full of giant phalluses, naked girls and guys, strange sex, music, and ideas. At his best, he created films like Gothic, and at his worst he gave us Salome's Last Dance, which is a hard-to-watch adaptation of an Oscar Wilde classic. It's strange.
Psychedelic film is more concerned with content than structure. At the forefront of a psychedelic film movement of the 60s, Ken Russell went for the gusto, trading happy endings for wild imagery. I do think that many of his films lack a definite ending. They end abruptly, strangely, and on a sour note. You aren't meant to like it or hate it. But you've been somewhere nonetheless. In the case of Gothic, Altered States, Tommy, Lisztomania, Mahler, Crimes of Passion, Women in Love and others, the protagonist's mind reaches a climax of color and sensation, and while we aren't really sure what happens in the story, we come to realize that a greater story is being told.
When an artist has put out as many films as Ken Russell, you try to look at the whole body of work, not just individual films. Some of his films can be enjoyed by themselves, and some are really meant for the fans only. The ones you should start with would be The Boyfriend, Women in Love and Gothic. If you like what you see there, keep going. At his most sober, he made The Rainbow and The Devils. In the throes of madness, he made Lair of the White Worm. His films are beautifully written and acted. Frequent collaborations with Oliver Reed, Glenda Jackson, Sammi Davis have yielded tremendous results. The body of work is astonishing. He was doing things that no one else was doing, or would do. While we might not have made the same choices, we love that filmmakers like Ken Russell had the wherewithal and determination to do it.
We can see his influence in the films of Oliver Stone, Terry Gilliam, Steven Spielberg, and Peter Greenaway. The films are playful, extreme, strange, and oddly charming. There is a visual language he uses, which pierces the intellect like a giant dildo. He works on a sensual level, assaulting the viewer with new images they haven't seen before.