MAC Unique Info

The following helpful advice was taken from the Classical MIDI Archives:

Mac users:
In order to play these sequences on a Mac, you should run them through ResEdit to change the File-Type to "Midi" and File-Creator to "MOUP". Although this requires an extra step, you'll at least be able to access these archives. Scott A. Lehman suggests downloading Midi-Typer from HERE, a drag-and-drop Mac utility to change file types to Midi.

BigSky MacEzine recommends the following :
ÁZak-- a program that lets Mac users play MIDI directly from the WWW.

Also see the Excellent MAC User MIDI help from Twin Cities MIDI page

Note : I am not a MAC user, so I can't test out these recommendations myself.
I do know, however, that these files have been successfully ported to MACs by others. So if the above info is not enough, seek out other knowledgable MAC folks for help! (See some of the links below)
If you find any useful troubleshooting solutions, let me know and I will include the information here to help others.

MIDI compatibility (Generic Info)

During the past few months, as I have "surfed the net" , I have learned more about MIDI than I really wanted to know, since I have had problems playing some of the files which I have downloaded. I have included a nutshell description which describes the most frequently encountered compatibility problem, and recommends the usually successful solution.

For people with a greater thirst for knowledge, the following web sites provide the gory details, or links to gory details: (Links Current as of 8/1/97)
Harmony Central
Twin Cities MIDI Home Page
MIDI Home Page


(some of this is PC specific but it generally applies to MAC platforms also)

The most common compatibility issue which crops up when trying to playback MIDI files created on another setup derives from the fact that there are three "versions" of MIDI. If a file is created on a system set-up with one of these three versions, it may or may not playback properly on a system which has been set-up for another of these three versions of the MIDI standard. Fortunately, if there is a problem, a simple adjustment to the setup is usually all that is required to allow for playback of files created on other systems.

The heart of the problem, at the risk of oversimplifying, is this: MIDI systems can send the music information to 16 different "channels" to playback the data recorded on the various "tracks" of the MIDI file. These "channels" are numbered Zero through 15 (although some software may show them as number 1 through 16).

One version (actually a sub-set )of the MIDI standard, often called "Basic MIDI", uses only four of these channels, specifically channels number 12 through 15. Channel 15 is typically used for percussion.

A second version (the true "level-1 standard") of the MIDI standard, called General MIDI (GM), uses channels 0 through 15, with percussion typically on channel 10.

A third version of the MIDI standard, Roland's GS standard, is supposed to be a superset of the GM standard, which expands upon the GM standard to provide additional sound and control capabilities. In principle, files created with the GS standard should play-back on systems set-up for the GM standard, with the superset GS commands ignored. In practice, some incompatible commands may cause the GM systems to be unable to process the files.

If you are trying to playback a MIDI file created on another system, and you are not getting any sound, the first thing to do is to locate your system's MIDI map file and make sure that sound drivers are properly set-up in all 16 channels.

During the installation and set-up of a sound card or controller system, drivers may not be installed for all of the 16 channels. Some installation software will install sound drivers in all 16 channels, some will install only channels zero through 10, some will install only channels 13 through 15.

Installing the sound drivers for all of the 16 MIDI mapper channels will usually solve the problem. Alternatively, you can edit the MIDI file to direct the output from a channel without a sound driver, to one of the channels which does have a sound driver installed.

Some software just can't read-through or ignore some of the extra GS commands in a GS-MIDI file. The symptom I personally encounter is that the file won't load into the playback program. Error messages vary. As yet, I know of no easy fix.

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This FAQ courtesy of Warren Trachtman