Many Anderson shows have a vocal theme of some sort. Wasn there one planned for Thunderbirds that wasn used?
Yes. There were actually plans to replace the reprise of the “Thunderbirds” march over the end credits with a song called “Flying High.” Cooler heads prevailed at the last minute and the song was not used during the credits. It does, however, make an appearance in the series’ final episode, “Ricochet”, on the pirate radio station run by deejay Rick O’Shea.