“Silly Thing” has a somewhat complicated history. Of which, Wikipedia says …
The original version of the song, on which Paul Cook sings lead vocals and Steve Jones plays bass guitar, was recorded with engineer Steve Lipson at Regents Park Studios in London in April or May 1978. The recording of further guitar overdubs and the final mixing took place at Rockfield Studios in Wales with producer Dave Goodman in late May 1978.
This original version of “Silly Thing” appeared on the movie soundtrack album of The Great Rock ‘n’ Roll Swindle and was used for the single in New Zealand, France and Japan.
A different mix of this original version, with Cook singing the verses and Jones singing the chorus, was released in 1988 in Japan, along with an outtake from the same recording sessions, the original version of the Jones/Cook composition “Here We Go Again”.
In the second week of March 1979, Jones and Cook went into Wessex Studios in London with engineer Bill Price and recorded a new version of the song. On this version, bass guitar was played by Andy Allen of the Lightning Raiders, who later in the year formed The Professionals with Cook and Jones.
This version of “Silly Thing” was used for the single in the UK, Australia, West Germany and Portugal. It appeared on the 1992 Sex Pistols compilation Kiss This.
The B-side to the Steve Jones single is “Who Killed Bambi?” written by Edward Tudor-Pole, with lyrical assistance from Vivienne Westwood. It’s really … something …