Switched-On Bach (1968) was an early album demonstrating the use of synthesizers as a genuine musical instrument. As an early user of Robert Moog's first commercially available synthesizer, Carlos helped pioneer the technology, which was significantly more difficult to use than it is today. Multitrack recording techniques played a critical role in the time-consuming process of creating this album. Switched-On Bach was one of the first classical albums to sell 500,000 copies, and (eventually) to go platinum.

The son of fado (Portuguese folk songs) singer and fado house owner, Lucilia Do Carmo, Carlos Do Carmo (born Carlos Manuel de Ascencao Almeida in Mouraria, Lisbon, in 1939) has established his own reputation as a passionate singer of Portuguese folk songs, as well as one of the most distinctive voices in the world.