Warning: Wikipedia contains spoilers.
Filmed in 1971, Dahl's screenplay follows his book's basic storyline fairly closely. Mel Stuart's direction however takes some parts of the movie in a slightly darker direction than the book. One sequence, the boat ride on the chocolate river, in hindsight shows the obvious influence of psychedelia.
It was not a full musical in the usual sense, featuring only six songs. Some were notably well received, including "The Candy Man Can", and "The Oompa Loompa Song". "Cheer Up, Charlie" is regularly edited out of TV screenings, presumably because the song is widely (but not universally) disliked.
It stars Gene Wilder as the eccentric chocolate candy maker, Peter Ostrum as Charlie, and Jack Albertson as Grandpa Joe.
Amongst its notable cameos are Tim Brooke-Taylor.