<Tr> <Td> "Castles in the Air" (1971) </Td> <Td> "American Pie" (1971) </Td> <Td> "Vincent" (1972) </Td> </Tr> <Tr> <Td_colspan="2"> <Table> <Tr> <Td> "Castles in the Air" (1971) </Td> <Td> "American Pie" (1971) </Td> <Td> "Vincent" (1972) </Td> </Tr> </Table> </Td> </Tr> <Table> <Tr> <Td> "Castles in the Air" (1971) </Td> <Td> "American Pie" (1971) </Td> <Td> "Vincent" (1972) </Td> </Tr> </Table> <Tr> <Td> "Castles in the Air" (1971) </Td> <Td> "American Pie" (1971) </Td> <Td> "Vincent" (1972) </Td> </Tr>

What is don mclean's american pie song about