A 78rpm record, also known as a shellac record or simply a 78, is an early method of storing and reproducing sound recordings. It is an analog disc format that was widely used from the late 19th century until the mid-20th century. The number "78" refers to the rotational speed of the record, which spins at roughly 78 revolutions per minute.
These records were primarily made of shellac, a resin obtained from the excretion of certain insects, which was mixed with fillers and pigments to create a brittle and easily breakable material. The recordings on these records were created by etching grooves into the surface using a mechanical cutting process. The stylus of a phonograph or gramophone would then trace these grooves, converting the physical vibrations into sound waves that could be amplified and played through a speaker.
78rpm records typically have limited playtime, usually less than five minutes per side, and were often single-sided until the early 20th century when double-sided records were introduced. They were commonly used to store various types of music, ranging from classical compositions to popular songs, resulting in a diverse range of musical genres being available on this format.
Although 78rpm records became gradually less popular after the introduction of the long-playing (LP) vinyl record in the late 1940s, they remain significant for their historical value and have become sought-after collectors' items.
The term "78rpm record" is derived from the characteristics of the record itself. Here's the breakdown:
- 78rpm: This refers to the speed at which the record is intended to be played. The number "78" signifies the revolutions per minute (rpm) required for the record to be played at the correct speed. Early phonograph records, manufactured from the late 19th century through the first half of the 20th century, were commonly played at 78 revolutions per minute.
- Record: The term "record" refers to a disc-shaped object that stores sound in grooves. In the context of "78rpm record", it specifically refers to the type of audio recording medium that rotated at a speed of 78rpm.
Overall, the term "78rpm record" combines the speed at which it is played with a general reference to disc-shaped sound storage.