The Bach Society recommends the use of Speedy Midi in conjunction with our practice learning files. The program has been written by Holger Hoffmann who has released it under GNU Public License (which means it is free to anyone as long as Holger is given attribution).
To obtain your copy of Speedy Midi click on the download button. Your browser may require permission before download commences; and you will be asked whether you want to Run or Save the program. Choose Save and in the Explorer dialog that follows choose to save in the normal Downloads folder (or your dektop if you prefer):
Once it is downloaded click the Open button in your browser and Speedy Midi will install itself. It does not create a desktop icon, so you need to create one by using explorer to locate C://Program Files (x86)/bin/speedymidi.exe; right click on it and choose 'Send To→Desktop (Create Shortcut).
Once you have downloaded the program you will need to tell your computer to use it for midi files.
In Windows Vista or Windows 7/8 choose Start→Control Panel and open 'Default Programs' (via 'Programs' in Category view); then click 'Associate a file type or protocol with a program'.
Scan down the list to find and select '.mid'. Click on the 'Change' button and in the resulting window click on the 'Browse' button (the default assignment will be Windows Media Player).
Again locate C://Program Files (x86)/bin/speedymidi.exe and left click on it, then click the 'Open' button; finally click 'Close' to complete the process.
Using Speedy Midi
If you have followed the installation instructions for Speedy Midi you can run any of the practice files marked with 
.
When first you click on a file you will get warning messages; clear the check box in the first one to inhibit it in the future, and choose Run. Clear the check box in the second and choose Continue.
Speedy Midi will open and show a display of the music pitches for all parts. The playback speed is controlled by the control in the top left hand corner (next to the Play button). To change the playback volume of a part double-click in the left hand column in the part (you will probably find that you cannot hear the other parts in '100 carols' midis without reducing your volume to 50%). Stop playback and click back in the music to re-hear a section. Stop and click within a particular chord then key F7 to listen to the chord continuously.
Note on Apple Quick Time
If you have Apple Quick Time installed on your computer it may take over midi files on web pages - that is, it runs where Speedy Midi should. If this occurs, right-click with your mouse and then left-click on 'Save Target as..' in the pop-up menu. Save the file in your Music folder. When you run it from there, Speedy Midi will open.
Other Apps
If anyone finds better apps for this purpose please let us know.