Shanties were for singing but whilst working.
all singing is fun as far as i am concerned , otherwise i would not do it.
I have yet to hear of singing used as a form of torture.

A blast of Black Sabbath makes plants bloom, says radio gardener. ... Beardshaw says using rock music as a nutrient appears to create larger flowers and they are more disease-resistant. The test came about because one of his horticultural students wanted to write a dissertation based on the effects of music on plants.