The voice you hear belongs to Lisa Lougheed. I have no idea who is on the instruments. I do not own this song. I do not own this cartoon. But, this cartoon owns.
I love this part, this is where Cyril wants to run Mammoth power out of business on account of a massive electrical bill run up by the pigs, so he has the pigs and the bears build this huge dam, and while this song plays one of the pigs gets chased by a cement mixer, and god did I always laugh when I saw it.