In Windows the files type is defined by the extension, such as .mid, .exe, .txt.
Most servers now add an acceptable header to midi files.
If you have checked all the coding on your page and the MIDI file does not play when you test it on the web, it is probable that the MIME type is not configured on your Server. You can confirm the MIME-type being sent with your MIDI file by viewing the page souce while on line. Contact your Webmaster and request that the following MIME type is added. This site is owned, designed and produced by Business Technologies, operated by Les.