It featured music by three of the Workshop's most prominent composers, John Baker, David Cain, and Delia Derbyshire.

In 2002, the compilation was remastered by Mark Ayres, and re-released with two bonus Derbyshire songs; the original composition "Time to Go" and her version of "Happy Birthday".

The selection demonstrated many of the methods used by the composers at the Radiophonic Workshop, including musique concrète tape editing and their use of primitive early electronic oscillators.

It featured mostly original compositions, except for Baker's arrangements of the traditional "Boys and Girls" and "The Frogs Wooing", and Derbyshire's version of Johann Sebastian Bach's "Air".

It was reissued on 29 August 2020 as part of the Record Store Day exclusive 6-CD box set Four Albums 1968 - 1978.