The groove modulation on an LP is typically in the form of a continuous spiral pattern, starting at the outermost edge and gradually moving inward towards the center of the record. The varying width and depth of these grooves represent the variations in sound waves, allowing the recorded music to be reproduced when the needle (stylus) of a turntable traces these grooves.
The specific shape and characteristics of the grooves are determined by the recording process. Typically, the grooves are "cut" into the master lacquer disc using a specialized engraving machine called a lathe. The variations in the groove walls correspond to the fluctuations in the audio signal, capturing the musical content and preserving it as physical undulations on the record.
When the record is played on a turntable, the stylus of the cartridge reads the groove modulations and converts them back into electrical signals. These signals are then amplified and played through speakers, recreating the recorded audio.
The term "groove" is often used interchangeably with "track" when referring to the divisions of music on an LP. Each groove represents a specific section or song on the record. The turntable can be moved to different positions along the groove to play the desired portion of the music.
Overall, the groove on an LP serves as a physical medium for storing and playing back audio information, enabling listeners to enjoy recorded music in the analog format provided by vinyl records.