Paint Your Wagon (1969), a Western musical starring Lee Marvin, Clint Eastwood, and Jean Seberg, wasn't exactly controversial in the way that films like A Clockwork Orange or Midnight Cowboy were around the same era - but it did raise eyebrows for a few reasons:

1. Polyamory Theme

At the heart of the plot is an unusual romantic arrangement: two men sharing one wife in a frontier town. This menage a trois was highly unconventional for mainstream cinema in 1969, especially in a genre (Westerns) associated with rugged individualism and traditional masculinity. While it didn't provoke protests, it certainly confused or unsettled more conservative audiences.

2. Singing Cowboys

Clint Eastwood and Lee Marvin - both known for tough-guy roles - singing in a musical was seen as a strange casting choice. Marvin's gravelly, off-key performance of "Wand'rin' Star" became a UK hit, oddly enough, but critics and viewers were divided. It wasn't controversial per se, but it was mocked and ridiculed, even at the time.

3. Massive Budget and Production Problems

The film was infamous in Hollywood for its bloated budget and chaotic production, with costs ballooning to over $20 million - a huge sum in the 1960s. It became a symbol of Hollywood excess and mismanagement, which was a topic of industry controversy, though not public scandal.

Summary

Paint Your Wagon slightly challenged social norms with its unorthodox relationship dynamics and confounded expectations by turning tough actors into musical leads. It remains a fascinating, flawed relic of the era - more of a curious oddity than a true controversy.