<P> The narrator warns mothers not to let their children become cowboys because of the tough and busy life of cowboy culture . </P> <Table> <Tr> <Th> Chart (1975--1976) </Th> <Th> Peak position </Th> </Tr> <Tr> <Td> US Hot Country Songs (Billboard) </Td> <Td> 15 </Td> </Tr> <Tr> <Td> Canadian RPM Country Tracks </Td> <Td> 36 </Td> </Tr> </Table> <Tr> <Th> Chart (1975--1976) </Th> <Th> Peak position </Th> </Tr> <Tr> <Td> US Hot Country Songs (Billboard) </Td> <Td> 15 </Td> </Tr>

Who sang mama don't let your babies