MIDI, which stands for ‘Musical Instrument Digital Interface’ is a standard for connecting electronic instruments, computers and related audio devices. There is also a file format for exchanging data and there are many choral practice tracks to be found in this format.
A MIDI file is really much more like printed music than an audio file and, as a result, most computers and portable devices like smartphones and tablets, are unable to play them without specialist software. One exception to this rule is PCs where Windows Media Player can often play a MIDI file. Sadly WMP sometimes simply does not work. To make better use of MIDI files software such as Sweet Midi Player can be used to have better control over the sound; the instruments used, tempo, pitch and speed can all be varied.
Most people just want to play the music and practise their part and don’t want the complexities of such software. However, it is quite possible to convert MIDI files into MP3s that can be played on almost anything.