With a huge global audience watching on pay-per-view TV, the angelic Jamaican introduced his song this way: "We got two kinds of people living on this planet -- one kind wants to save the planet, while another kind wants to destroy."

Speaking of those who cut down rain forests and pollute the earth, Mr. Cliff pointed his finger skyward and declared, "We the people ought to put them under arrest because they are criminals."

Many in the young crowd cheered and joined Mr. Cliff in the chorus as he sang of those who pollute: "Stop, you are a criminal."

But one Woodstock participant -- Pepsico, the festival's main commercial sponsor -- was not in tune. TV viewers suddenly found the spirited sing-along interrupted by an ad offering a reminder to "be young, have fun, drink Pepsi."

Pepsi's abrupt on-screen appearance was clumsy yet timely.

While no specific polluters are named in Mr. Cliff's song, Pepsi was one of the villains singled out by Greenpeace in various festival forums.

Unknown to most festival-goers, Pepsi worked assiduously behind the scenes to muzzle Greenpeace, threatening at one point to withhold financial backing if Greenpeace was not reined in. Due to the company's pressure, mini-billboards mentioning Pepsi's role in "The Plastics Recycling Scam" were not displayed.

However, the educational display in the Greenpeace tent pointed out that Pepsi has been a major plastics polluter since the company moved away from glass bottles years ago.

With our country overflowing in plastic garbage, Pepsi has begun shifting both production and disposal of plastic bottles to India. Dumping the mess on countries like India is a good way to avoid our environmental and labor laws, but it is exactly the kind of destructive activity that singer Jimmy Cliff wants criminalized.

Rather than bring back glass bottles, Pepsi persists in the production of plastic, which emits toxic chemicals such as chlorinated benzene that can cause cancer and birth defects.

Pepsi hails plastic recycling as a solution to the waste problem. But millions of the used plastic bottles exported to Asia are not reprocessed; they are burned or buried. When Greenpeace investigator Ann Leonard visited a plant in India where U.S. soda bottles are shipped, factory officials told her that up to 40 percent could not be recycled.

Disposing of plastic bottles creates big problems, whether they are burned (producing dioxin and other toxins) or buried (not biodegradable) or recycled (reprocessing is dirty and dangerous to workers in India and elsewhere).

The campaign urging Pepsi to return to reusable glass bottles is part of Greenpeace's Toxic Trade Project, which is targeting corporations that dump waste in Africa, Asia and Latin America rather than convert to clean production at home.

Nowadays, through ad and sponsorship strategies, companies with dubious environmental policies are able to "greenwash" their images to appear ecologically responsible. One method is by hailing faulty "recycling" efforts.

Pepsico, which underwrites TV public affairs shows, apparently saw its festival sponsorship as buying censorship of criticism. But Woodstock promoter Michael Lang saw it differently and let a Greenpeace leader speak from the stage.

Corporate sponsorship holds more sway over news media than over music concerts. Perhaps that is why the American public is so well-informed about allegations against celebrities like Michael Jackson and Tonya Harding but so uninformed about accusations against corporate celebrities like Pepsi.

We hope to see the Greenpeace-Pepsi dispute included in the Woodstock '94 movie, which, thankfully, is not sponsored by Pepsi.

Maybe we even will get to see Jimmy Cliff singing "Save Our Planet Earth" -- without commercial interruption.