Some visitors to this site have reported problems with playing the various MIDI files that are available for download. Sometimes the file can not be opened. Sometimes it appears to be playing but produces no sound, or sometimes it plays but does not sound like the instrument described. This page gives a basic outline of how these problems occur, with suggestions on how to solve them on Windows or Android devices. Sorry, I don't have any Apple devices - but they just work, don't they? The notes following are current at November 2025, but like many things on-line they may be out-of-date by the time you read them.
Some web browsers will change the type of the MIDI file during download by adding a second extension ".rtx" to the end of the file name. "filename.mid" may become "filename.mid.rtx", which most MIDI players can not understand. The contents of the file are not changed; only the ".rtx" is added to the file name. If this happens, just rename the file and remove the ".rtx", and it will probably play correctly. Or, preferably, use a different web browser that does not modify your downloads.
MIDI files do not contain any actual sound. All they contain is a long list of instructions which tell a "MIDI synthesiser" how to generate the sounds required. For every note in the piece of music there is an instruction which says (in essence): "at this time, play this note on that instrument at this volume for that long". A "MIDI player" program or app reads these instructions and sends them to the synthesiser (or "synth"). The synth can be an external hardware device connected by an electrical cable, or a "virtual synth" in software inside a computer or mobile phone.
A virtual synth needs a "sound font" to describe the characteristics of each musical instrument, just as a word processor needs a text font to describe the characteristics of each typeface. Basic sound fonts can describe the full set of MIDI instruments in about 10 megabytes of data, while a high-class sound font for a grand piano alone can occupy several hunded megabytes. Prices vary accordingly.
Sometimes the MIDI player, synth, and sound font are all contained in one software program, but often they are in two or three separate components. Windows PCs contain a virtual synth and a basic sound font ("Microsoft GS Wavetable Synth" or similar) which programs can use if they wish, but Android mobile phones do not.
On Windows PC systems "VanBasco's Karaoke player" has long been the MIDI player of choice. Its original web site has disappeared, but the program is still easily found on-line.
"VLC Media Player" is currently very popular on Windows and Android devices. It uses a third-party "virtual synth" ("Fluid Synth") rather than the PC's internal version, but the standard installation of VLC does not include a sound font. As a result, VLC can open MIDI files and they will appear to be playing, but they produce no sound. A suitable sound font file (with installation instructions) can be downloaded free from https://schristiancollins.com/generaluser.php
However, the easiest solution to the "no-sound" problems on Android phones is to install a dedicated "all-in-one" application which includes a MIDI player, virtual synth and matching sound font. The "Clef MIDI Player" works well.
The General MIDI (GM) specification defines a hundred or so standard instrument sounds which all synthesisers should be able to produce. Instrument 1 is always a grand piano; instrument (or "patch") 57 should always sound like a trumpet; patch 74 is always a flute, etc. Most of the organette music files on this site use General MIDI patch 21 (Reed Organ) or 23 (Harmonica).
The actual sound that you will hear from any of these "virtual instruments" depends on the quality of the MIDI player, the synthesiser, and especially the sound font, all of which can vary from very poor to excellent. Some low-end players have trouble interpreting the MIDI files correctly, and may not produce an accurate (or even approximate) representation of the target instrument. Professional audio and MIDI equipment can produce very impressive results, but is not needed to enjoy the (very basic) MIDI files on this site.
Below are two music files which can be used to check the results on
your system. The first is an MP3 audio recording of a vintage
Gem Roller Organ playing roller
#23, "Where is my boy tonight" (Lowry, 1877). The second is a MIDI file
of the same piece, transcribed from the same roller and using the
General MIDI "Reed Organ" patch 21. The two files will not sound exactly
the same, but the general nature and quality of the sound should be
similar in both cases. (Except that the "wavering" effect in the MP3
recording is a peculiarity of the roller organ, and will not appear in
the Reed Organ file). The MIDI file should produce an acceptable sound
quality, with sustained organ notes and no pauses, gaps or obvious
defects in the music. If the results are not satisfactory, they can
usually be improved by changing to a different MIDI player or sound
font file.
Gem roller #23, MP3 audio recording (156kb, 40 seconds).
Gem roller #23, Reed Organ MIDI file (2kb).