What is the original invention of the edison phonograph? Between 1920 and 1922, the phonograph industry was growing fast–over a hundred thousand edison phonographs and 5 million edison-format records had been produced (Leonard DeGraaf, Confronting the Mass Market: Thomas Edison and the Entertainment Phonograph, Business and Economic History Vol 97 Nod. 1) 24 (19Fall 1995):89-90), and the word “groove” was being used for recordings ( http://www.etymonline.com/index.php? accessed 20140212). terms = groove.

As the phonograph became more familiar to the general public in the early 20th century, the average person would have been increasingly aware of records, and what a record sounded like when it was not in the groove–sudden and dissonant–and consider that early “talking” movies often had the audio track playing on a phonograph. What is the sound of a scratching or skipping record, and the audio joke that is the sound persists even today in an era when vinyl records are a niche market.

As such, it is conjecture, but a plausible one, that “in the groove” was adopted linguistically to represent the antithesis of this dissonance.