A MIDI Player is a device or program capable of converting a MIDI file into audible music.
After the invention of MIDI, it became possible to produce compact data files resembling musical scores. At first, these were used to control musical instruments but after some time, synthesiser-like equipment was produced which lacked keyboards which could however be controlled via MIDI sockets. This was later adapted to accept ROM cartridges containing these files and later still incorporated in domestic and dashboard computers. This enabled music to be downloaded from online services and saved on tape drives, a process which was encouraged by the music industry as it made the distribution of music inexpensive and convenient. Finally, often as part of a portable CD Player, music could be stored on solid-state RAM. This reduced power consumption but meant that the player had to be constantly provided with mains or battery power to retain the files. Their capacity was also rather small. There are also cheaper versions which consist solely of solid state hardware, listened to through headphones, which have a very long battery life.