Folksingers are Canada’s ambassadors for UNICEFKnight-Ridder News ServiceYears from now, some anthropologist may happen upon the village of Yompoupata, on the shores of Lake Titicaca, high in the Bolivian Andes and there she might find the indigenous people, descendants of the Incas, walking and chanting in unison in a curious ritual passed down from generation to generation:‘‘Uno, dos, tres, quatro ... Schlemiel, shlimazel/ has-senpfeffer hoochie-coochie ..And the anthropologist, if she is very wise, would know that Sharon, Lois and Bram had been there.True, the three children’s folksingers arc more commonly found in concert auditoriums, but last month they spent two weeks in the Bolivian highlands under the auspices of UNICEF, the United Nations children’s fund. (The trio are Canada’s official goodwill ambassadors for UNICEF.) Their journey was taped by Canada’s Global Television and should air late this year in Canada; an American airing is also possible.“It was like stepping into another world,” said Bram Morrison. The people were very shy. It took us a while to connect. But connect they did, and that included a fair amount of song-swapping.“They got to loving it, said Sharon Hampson.Well, sure. Why should kids in the mountains of Bolivia be any different from kids in Canada and the United States, where Sharon, Lois and Bram have been recording and touring for 10 years and appearing on TV for five?Music is great fun and the world is filled with a lot of terrific songs that are there for the singing.LARRY’S SEAFOODSPECIAL