<Tr> <Td> </Td> <Td> "Believe It or Not" (1981) </Td> <Td> "When She Dances" (1981) </Td> </Tr> <P> "Believe It or Not" is a song composed by Mike Post (music) and Stephen Geyer (lyrics) and sung by American singer Joey Scarbury . It serves as the theme song for the television series The Greatest American Hero . The track was later included on Scarbury's 1981 debut album America's Greatest Hero . </P> <P> The theme song became a popular hit during the run of The Greatest American Hero . "Believe It or Not" debuted in the Top 40 of the Billboard Hot 100 on June 13, 1981, eventually peaking at number 2 during the weeks ending August 15--22, 1981, kept off the top spot by "Endless Love" by Diana Ross and Lionel Richie, and spending a total of 18 weeks in the Top 40 . On the Adult Contemporary Chart, "Believe It or Not" went to number 3 . It also peaked at the number 1 position on the Record World chart . It was also used in the 2009 movie "Super Capers". </P> <Table> <Tr> <Td> <H3> Weekly charts (edit) </H3> <Table> <Tr> <Th> Chart (1981) </Th> <Th> Peak position </Th> </Tr> <Tr> <Td> Australia KMR </Td> <Td> </Td> </Tr> <Tr> <Td> Canada RPM Top Singles </Td> <Td> </Td> </Tr> <Tr> <Td> Ireland (IRMA) </Td> <Td> 19 </Td> </Tr> <Tr> <Td> New Zealand </Td> <Td> </Td> </Tr> <Tr> <Td> U.S. Billboard Hot 100 </Td> <Td> </Td> </Tr> <Tr> <Td> U.S. Billboard Adult Contemporary </Td> <Td> </Td> </Tr> <Tr> <Td> U.S. Cash Box Top 100 </Td> <Td> </Td> </Tr> </Table> <Table> <Tr> <Th> Chart (1982) </Th> <Th> Peak position </Th> </Tr> <Tr> <Td> Ireland (IRMA) </Td> <Td> 28 </Td> </Tr> </Table> </Td> <Td> <H3> Year - end charts (edit) </H3> <Table> <Tr> <Th> Chart (1981) </Th> <Th> Rank </Th> </Tr> <Tr> <Td> Australia </Td> <Td> 9 </Td> </Tr> <Tr> <Td> Canada </Td> <Td> 47 </Td> </Tr> <Tr> <Td> New Zealand </Td> <Td> 21 </Td> </Tr> <Tr> <Td> U.S. Billboard Hot 100 </Td> <Td> 11 </Td> </Tr> <Tr> <Td> U.S. Cash Box </Td> <Td> 8 </Td> </Tr> </Table> </Td> </Tr> </Table>

Who sings the song i'm walking on air