been developed that correct wow and flutter by tracking various spurious things on the tape or film, which can be re-purposed as timing references. A system developed by Plangent Processes substantially reduces wow and flutter of very high rates to extremely low levels, with a substantial improvement in quality. The software Capstan by Celemony analyzes the already digitalized musical material and uses varispeed playback to eliminate wow and flutter. See also Rumble measurement Phonograph Wow and flutter measurement Audio storage Sound recording