Gramophone (Sound recorder) or the Phonograph in 1800s used a small disc like flat to record sound which in future bring the concept of Compact Disc( CDs).
Explanation:
Several attempts has been made to revise the sound recorder system. In first two attempt Gramophone used cylinders for recording music then it started using a flat glass like disc that in later stage bring the concept of compact disc (CD) in popular music.
Gramophone has a diaphragm on the top and a cylinder like structure in the middle with spiral grooves. It takes much time before to correct any technical error in music recording in Phonograph but now its become easier to correct instantly.