Difference between revisions of "MOD music file"

Latest revision as of 22:05, 18 October 2022

Module file (MOD music, tracker music) Amiga MOD music files - music stored in module files created with trackers. MOD came many years before MP3s and also set a unique standard for how music sounds from a computer.

MOD files originated on the Amiga, but because of their flexibility and the extremely large number of MOD files available, MOD players are now available for a variety of machines (IBM PC, Mac, Sparc Station, etc.)

The samples in a MOD file are raw, 8 bit, signed, headerless, linear digital data. There may be up to 31 distinct samples in a MOD file, each with a length of up to 128K (though most are much smaller; say, 10K - 60K). An older MOD format only allowed for up to 15 samples in a MOD file; you don't see many of these anymore. There is no standard sampling rate for these samples.

The sequencing information in a MOD file contains 4 tracks of information describing which, when, for how long, and at what frequency samples should be played. This means that a MOD file can have up to 31 distinct (digitized) instrument sounds, with up to 4 playing simultaneously at any given point. This allows a wide variety of orchestrational possibilities, including use of voice samples or creation of one's own instruments (with appropriate sampling hardware/software). The ability to use one's own samples as instruments is a flexibility that other music files/formats do not share, and is one of the reasons MOD files are so popular, numerous, and diverse.

15 instrument MODs, as noted above, are somewhat older than 31 instrument MODs and are not (at least not by me) seen very often anymore. Their format is identical to that of 31 instrument MODs except:

1. Since there are only 15 samples, the information for the last (15th) sample starts at byte 440 and goes through byte 469.
2. The songlength is at byte 470 (contrast with byte 950 in 31 instrument MOD)
3. Byte 471 appears to be ignored, but has been observed to be 127. (Sorry, this is from observation only)
4. Byte 472 begins the pattern sequence table (contrast with byte 952 in a 31 instrument MOD)
5. Patterns start at byte 600 (contrast with byte 1084 in 31 instrument MOD)

A Mod Music File aka Module File can be, in an over simplified way, considered a mixture of MIDI and WAVE. The MIDI file is constrained by the instruments expressed within your sound card while mod has sequencing information and actual instrument samples. If you could fuse the music information from a MIDI with these wave like samples you get the powerful software synthesizer sound of the MOD file with a very small and efficient file size! It is like having some of the quality of Mp3 and the tiny file size of MIDI with the editing power of MIDI where you can create, modify, and integrate your own samples.

Mod versus MIDI (old school)

In the late 1980s and through the 1990s those of us that enjoyed listening to and creating MOD files all pretty much agreed that MIDI was an inferior computer audio format. MIDI is an acronym for Musical Instrument Digital Interface and seemed to be the non-hackers way to share flat sounding anemic music. During the time period you had the most common choices of either MIDI or MOD.

MIDI is not simply a "file format" but rather a technology protocol. The MIDI protocol standard had its original purpose as a way to store and mix electronically synthesized music but by the time the personal computer became popular midi was adapted to a computer format. MIDI was originally a serial protocol that allowed different digital instruments to exchange information and control each other and not specifically created for the personal computer. MIDI had its purpose and that purpose was not aligned with those wanting a way to trade wave file quality music tracks from computer to computer.

MIDI was created around 1983, well before MOD files. It was not created specifically for personal computers whereas MOD files were created for the Amiga computer system by Amiga users. In this a direct comparison between MIDI and MOD is somewhat unfair. However critics of MIDI have existed going back to the 1980s shortly after its introduction. MIDI was designed for electronic keyboards and instrument control yet the designers never had other instruments in mind such as guitars when considering sound reproduction. Although guitar midi pickups exist, it has never sounded particularly well and remains disappointing to most musicians.

When comparing the file format of MIDI versus MOD you have to step back in time when they were both relevant as a way to trade music. If you had a fresh install of Microsoft Windows 3.1 on MSDOS 6.2 you might remember those sample midi files included with the system as well as a software midi player. By this time we were into the 1990s and MIDI was already 10 years old. People were trading music via BBS or the Internet (news groups and IRC) on their dialup connection and they were either trading, for the most part, MIDI files or MOD files. Die hard Windows nerds that were afraid to venture out of their comfort zone stuck to flat sounding MIDI files while the Amiga zealots and PC hackers were all trading MOD files with their sharp sound and unique expression of many popular songs. Neither MIDI nor MOD was a true replication of the original music (such as a wave file digital recording) but no one could afford to download 200MB of wave file, for a single Top 40 song, when the MOD file was only a few KB and would fit on a floppy disk if needed. MOD sounded more like the real thing than did MIDI.

It was said that you could rock to MOD while you would only fall asleep to MIDI. Pop music was in the dawn of being traded electronically, the emerging nightmare of the RIAA. Some early copyright music that was popular in MOD format was tracks like Technotronic's Pump Up the Jam and Every Breath You Take by The Police; the latter being without vocals but otherwise sounding like the compact disc version. It was not until the MP3 format became popular that you would hear about RIAA action against audio pirates being reported by the media. Neither MIDI nor MOD was a close enough rendition of these songs to upset the industry at the time.

As time progressed the MP3 format became extremely popular and could loosely be considered a hackers format for trading music that was nearly true to the original medium. MP3 files sounded close enough to the compact disc they were ripped from that they became all the rage. The only resistance to Mp3 in part came from dialup Internet users that didn't want to wait over an hour to download a single Mp3 and those die hard MOD creators and collectors that just loved the unique sound of MOD. By the turn of the century MOD had all but been forgotten and Mp3 was everywhere mostly due to Broadband Internet and Napster.

It is not relevant today and no one under the age of 40 even knows what the original MOD vs MIDI computer format debate is about. Furthermore, comparing the two as a computer file format doesn't take into consideration the original intent of either. However, if you had a personal computer in the late 1980s or well into the 1990s and you were into music, then you probably had a strong opinion and likely preferred MOD files over MIDI. Many game developers of the day used MOD music tracks for their games. MOD just sounded cool and MIDI was considered lame.

Summary of formats discussed:

MIDI - As a computer file it contains Instrument data instructions expressing how the sound should be produced by in part note, pitch, and duration.

MOD - The first modular format to represent music from pattern samples controlled by a sequencer.

MP3 - MPEG Audio compressed files. The .mp3 files are WAVE files that are compressed with a lossy yet acceptable algorithm.

software

ProTracker

ProTracker - for AmigaOS

Fasttracker II

FastTracker II is a singular piece of software that helped define trackers, demoscene, and the music produced with it. This was an MSDOS program very popular in the 1990s. A project now exists to provide a clone of Fasttracker 2 that runs on modern operating systems like Windows 10 and MacOS. The clone is built in SDL, a cross-platform media library, the work of Olav “8bitbubsy” Sørensen. [Fasttracker 2 Clone].

ImpulseTracker

xmp

Console, Linux, tested on Ubuntu / Mint

The Extended Module Player, or xmp, is a portable command-line module player. Xmp plays many mainstream and obscure module formats including Protracker (MOD), Scream Tracker 3 (S3M), Fast Tracker II (XM), and Impulse Tracker (IT). Libxmp loads the module and renders the sound as linear PCM samples in a buffer at rate and format specified by the user. Applications for libxmp include players, module information extractors, module-to-mp3 renderers, game music, etc. A smaller subset of libxmp is also available. below).

install

apt install xmp

MikMod

Console, Linux, ncurses interface full screen in console terminal / classic MOD player for Linux with curses or X interface. better keyboard commands than xmp. Good old fashioned mod file sound.

install

apt install mikmod

Warning, it is easy to accidentally delete a mod file with this program.

MilkyTracker

This one has a graphical user interface. It loads in a window but has a console feel, very reminiscent of the old Fasttracker 2. We tested version 0.90.85 on Linux Mint 18.3 and it functioned well.

Official description from the MilkyTracker Web Site: MilkyTracker is an open source, multi-platform music application for creating .MOD and .XM module files. It attempts to recreate the module replay and user experience of the popular DOS program Fasttracker II, with special playback modes available for improved Amiga ProTracker 2/3 compatibility.

The most recent version is from the web site or github. Ubuntu repository has it available however it wont be as current if you use apt.

apt install milkytracker

SchismTracker

Like MilkyTracker it runs in a gui window but looks console. This one dumps core when tested.

apt install schism