Brian May has condemned Japan's dolphin hunting, saying the slaughter of animals should end in the same way society has turned against slavery or witch-burning.
The Queen guitarist and animal rights campaigner said: "Every species, and every individual of every species, is worthy of respect."
May, in Tokyo for Queen's sell-out concerts at Budokan arena, added: "This is not about countries. It's about a section of humanity that doesn't yet understand that animals have feelings too."
Protesting against the dolphin hunt in the small Japanese town of Taiji, documented in Oscar-winning film The Cove, has become a cause for celebrities including Sting and Daryl Hannah.
Taylor McKeown, a silver medalist swimmer in the Rio Olympics, who has long been fascinated with dolphins, is now in Taiji to monitor the hunts.
Ric O'Barry, the dolphin trainer for the Flipper TV series, started the protests against the Taiji dolphin kill, and stars in The Cove, which depicts a pod of dolphins being herded into an inlet and getting bludgeoned to death, as blood turns the water red.
The hunters in Taiji and their supporters defend the custom as tradition, although eating dolphins is extremely rare in Japan. The Tokyo government also defends whaling as research.
May, who founded the Save Me Trust in 2009 to lobby governments on wildlife policy, said he opposes cruelty against all animals, including foxhunting and bullfighting. Both are also defended as tradition, but that is just an excuse, he said.
"I know Japanese people - so many. They're decent. They're kind. They're compassionate, but they don't know this is going on," he said of the dolphin killing. "These are mammals, highly intelligent, sensitive creatures, bringing up their children like we do, and they are being slaughtered and tortured."