[3] Following the success of her previous album, Switched-On Bach (1968), Carlos proceeded to record a second album of classical music performed on a modular Moog synthesizer from multiple composers, including Johann Sebastian Bach, Claudio Monteverdi, Domenico Scarlatti, and George Frideric Handel.

Its title is a play on words from Bach's set of preludes and fugues named The Well-Tempered Clavier.

In 1969, during the unexpected commercial success of her debut studio album Switched-On Bach (1968), Carlos and her friend, collaborator, and producer Rachel Elkind started work on a follow-up using the same formula as Switched-On Bach: performing selections of classical music on a modular Moog synthesizer.

The two decided on a "new switched on Baroque album" featuring multiple composers, including Johann Sebastian Bach, Claudio Monteverdi, Domenico Scarlatti, and George Frideric Handel.

[5] Canadian pianist Glenn Gould spoke about Carlos' rendition of Brandenburg Concerto No.