How to Open or Play .XMI Files

.xmi files are an old music file format similar to the midi format that was sometimes used in older video games.  The most well-known application that opens or plays .xmi files is probably WinAmp but it is not enabled to do so by default.  One needs to change settings, configure and associate the files with WinAmp first.  Go to Options/Preferences > Plugins/Input and choose Nullsoft MIDI player. Then go to File Types and choose the exotic music files types one wants to associate with the program.  Open and play the files you want to listen to.  It may be worth it to save the files in midi format so that they will be easier to work with in the future.