Talk:Musical Instrument Digital Interface

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[edit] too many directions for this article

Please provide opinions on splitting this article up. Information about MIDI file formats do not share the same purpose or scope as MIDI as a communications protocol.

I think we need individual articles for: - MIDI Overview and History (this article) - MIDI Specifications (Electrical, Protocol) (an article already exists for electrical) - General MIDI (GM) and MIDI File Formats - Any other MIDI subsets I haven't thought of here Infindebula 14:53, 11 January 2007 (UTC)

[edit] MP3 to MIDI

Is it possible to convert MP3 to MIDI format? I read elsewhere that it's not. JJMan 14:39, 17 July 2006 (UTC)

Try the free software Audacity. You can import midi files and export as PCM Wav or mp3. Great software, and its free!
There are some programs that purport to do this but it is by definition impossible to convert audible sound waveforms to MIDI commands 'perfectly'. Charlie Richmond 14:11, 17 July 2006 (UTC)
The denial above is expressed too weakly. I would say it is for the forseeable future impossible to convert an mp3 (or wav) file to MIDI with any kind of acceptable result. Only an extremely crude approximation might be feasible. −Woodstone 17:07, 17 July 2006 (UTC)
I think it depends on the recording. I'm sure you could trace say a piano solo with pretty high accuracy with the right tools but a complex layered mix would be FAR more complex. Any vocals would also hugely complicate the issue. Plugwash 01:27, 18 July 2006 (UTC)
There is no software available that can do the necessary pitch extraction from polytonal passages (i.e. music with more than one note sounding at a time). If you have a recording a musical riff, played as one note at a time, with no backing accompaniment, there are a number of professional tools which will extract note info to your sequencing environment. It works on unaccompanied vocals. Because piano solos tend to include lots of notes together, they generally don't work. Infindebula 14:58, 11 January 2007 (UTC)
One example of an actual possible pitch extraction from polytonal passages is a MIDI guitar, this is made possible by a hexaphonic pickup, where 6 separate inputs are used to determine the note of each string. —Preceding unsigned comment added by 68.146.37.30 (talk) 08:48, 26 October 2007 (UTC)
Of course it's possible. You listen to the MP3, then recreate the song in your sequencer. --Komet 12:22, 28 May 2007 (UTC)
Sure... convert the MP3 back to raw audio, convert it to the SystemExclusive format for a sampler and send the adio as a sound bank to the sampler using SysEx, then play the sounds back from the sampler using MIDI note-on messages. But that's ridiculous despite being theoretically possible. (Audacity goes the wrong way, from MIDI to MP3; OP asked about MP3 to MIDI.) Generally speaking, MIDI describes a mere handful of the parameters by which sounds are created (and perhaps affected over time), with the responding synthesizer and the rest of the audio chain determining how to transform that into audio. Most audio recordings consist of almost inextricably intertwined superimpositions of many notes from many sources. While you might be able to infer pitch => note, amplitude => velocity (I have an old device that attempts this for a monophonic source -- a Roland VP-70), and maybe even timbre => channel mappings, to do so for a complex audio recording is not currently within the bounds of computer capabilities (like Plugwash said) Dave Brown 15:23, 27 July 2007 (UTC)

[edit] dubious addition by anon

an anon recently added the following text which i just removed

Daisy chaining of multiple devices on a single port can be acomplished using the MIDI-THRU port. This technique is generally limited to three devices in a row due to latency. The latency is cauced by the fact that MIDI-IN ports are optically isolated. Instead of making a physical connection to pass electrical signals, the electrical signals arriving at the MIDI-IN port turn an LED on and off, which is read by a photo sensor. This physical break in the flow of electricity prevetns the forming of ground loops. It also introduces a small amount of latency. Generally after traveling thru 3 devices in a daisy chain, this latency beacomes noticable.

this seems to conflict with the following text from the MIDI-THRU article

The MIDI-THRU port avoids this delay by linking the THRU port to the MIDI-IN socket almost directly. The MIDI-OUT port is then used only for signals originating in that device.

Plugwash 09:09, 24 May 2005 (UTC)


Also, the digression to discuss opto-isolation is unnecessary, considering there is already an article on optical isolator's -- wackyvorlon
Touching on opto-isolation in relevance to the behaviour of MIDI Thru is entirely relevant, as many people are curious or misinformed about the characteristics of MIDI Thru. It should be noted that since the MIDI spec dictates that the only active component between MIDI In and MIDI Thru is an opto-isolator, there will be no appreciable latency on data that appears at the Thru port. The only counter-effect of a long MIDI daisy chain is in fact distortion of the MIDI signal caused by going through numerous opto-isolators.
This is entirely relevant to MIDI users and even researchers, but beyond the scope of an article on optical isolators. Infindebula 14:35, 11 January 2007 (UTC)

[edit] oxymoron

"almost directly responsible" is an oxymoron.

An oxymoron is properly a deliberate rhetorical or literary device, not just any old contradiction in terms. I don't see that your phrase is even a contradiction in terms, however, although it does seem to me excessively equivocal. It would help to have some context. Where in the article does it occur? TheScotch 07:17, 17 February 2007 (UTC)

[edit] DIN to D-SUB?

Does anyone know how to connect 5-pin DIN MIDI port to PC 15-pin D-Sub MIDI/joystick port?

-=[ tqn ]=-

Edit: Nevermind, found. http://www.midi.org/about-midi/electrical.shtml

[edit] MIDI controller merge

I think MIDI controller should be merged into this article. At least it should have a section with a {{main|MIDI controller}}, but I think compared to other info like the specification section it is not too much to be entirely merged. Comments?

[edit] useless image

As of the current revision [1] (possibly much older), the following image is put into the article's start:

Note names and MIDI note numbers
Note names and MIDI note numbers

This would be useful if the text inside the table can actually be read. But that's not the case, not even if you click on the image to see the enlarged image on the image page itself. I think rather than this image, we should instead put the actual table as wiki-markedup text somewhere in the article.

131.107.0.106 03:13, 8 June 2006 (UTC)

You can if you blow it up bigger. It's an SVG. See Image talk:NoteNamesFrequenciesAndMidiNumbers.svg — Omegatron 21:27, 10 June 2006 (UTC)

I think the image should be removed from wikipedia altogether, and perhaps replaced with one with more legible text and the removal of the staffs. They are misleadingly positioned. See comment on the picture itself. 216.162.240.250 19:45, 29 November 2006 (UTC)Greg

Have you noticed that all the note names and other stuff in the table is as for left-hand piano (lower voices on the right)? :) —Preceding unsigned comment added by T0ljan (talk • contribs) 13:56, 23 April 2008 (UTC)

[edit] Confused

Sorry, I'm not sure I get the "MIDI" concept. Doesn't it just basically mean, it's touch sensitive? :/ TommyBoy76 18:40, 31 July 2006 (UTC)

Where did you get that idea? MIDI is the whole system of sending musical notes in digital form, as described in the article. How can we make it more clear? —Keenan Pepper 20:50, 31 July 2006 (UTC)
I guess something isn't just clicking with me. It happens :-). Anyway, it is "sending musical notes in digital form", eh? Break it down, if I may. Send notes where? And weren't they already in digital form? You know... it's not exactly an acoustic piano that produces fake sounds. TommyBoy76 01:00, 1 August 2006 (UTC)
You can send then wherever you want. MIDI is just the language used to describe them. They weren't necessarily in digital form to begin with: say you have a MIDI keyboard hooked up to a computer. You can press any key whenever you want, as hard as you want, and the keyboard has to digitize the time and the velocity in order to send them to the computer via the MIDI connection. —Keenan Pepper 02:33, 1 August 2006 (UTC)
Ahh, so it's for computer purposes? TommyBoy76 19:22, 1 August 2006 (UTC)
Not necessarily. There's lots of MIDI equipment I wouldn't call "computers". It has microchips, but that should be obvious from the "digital" part. MIDI is a language that different pieces of electronic musical equipment use to talk to each other. How can we improve the article to make that more clear? —Keenan Pepper 22:58, 1 August 2006 (UTC)
Are you asking for my advice or are you wondering why I don't understand... I'd be glad to tell you both, if you want. :-) TommyBoy76 02:41, 2 August 2006 (UTC)
They go hand in hand. You seem like a reasonably intelligent native English speaker, so if you can't understand the article there's something wrong with it. —Keenan Pepper 03:42, 2 August 2006 (UTC)

Well, I consider myself a bit technology savvy, and I have a big vocabulary, but all of these words are preeettyyy big. I dunno, I think it's just me, though. The article is very well put together and well organized. But, if you want my advice, as an individual just introduced to MIDI, I was confused with two things:

One, the words were huge. And two, I found some explanations were somewhat broad; using words such as "information". What information? Where does it go? What does that solve? TommyBoy76 17:12, 2 August 2006 (UTC)

I'd be pleased to help by replacing the 'huge' words with multiple smaller ones and making the broad explanations less so but need you to provide more specific information on exactly what words are huge and what explanations are too broad. I will see what I can do about 'information' now... Charlie Richmond 15:40, 4 August 2006 (UTC)
I mean, even the first sentence is bit much.

Musical Instrument Digital Interface, or MIDI, is an industry-standard electronic communications protocol that defines each musical note or event in an electronic musical instrument or show device such as a synthesizer, precisely and concisely, allowing electronic musical instruments, computers and other show equipment to exchange data in real time.

Haha, what?? Anyway, I'd be glad to help you, but I'm not sure I have the patience, and I doubt you will either after you get done with me. :? TommyBoy76 18:20, 4 August 2006 (UTC)

[edit] Latency

Once and for all, it would be great if the neverending discussion about latency between a MIDI keyboard's key pressed and the final software sound produced would be discussed in this article. My question is: where does this latency come from, and is it true that cheap on-board cards produce higher latency than expensive soundcards? If yes, why is that so? Thanks. --Abdull 16:19, 25 August 2006 (UTC)

Almost certainly the latency in a MIDI setup is smaller than the latency between depressing a key on an acoustic piano and the hammer striking the string. −Woodstone 19:50, 25 August 2006 (UTC)
In a studio level setup this statement may be true, but many amateur musicians complain about lags, in, as you describe, pressing a button and hearing the sound. So the question remains: where does the latency come from some setups inhibit? --Abdull 09:22, 26 August 2006 (UTC)
Lags like that are not necessarily due to MIDI itself, and maybe problems like this could better be covered in other related articles. Computer, bus and disk speeds, auxiliary hardware that offloads some of the CPU's work, availability of multiple CPUs (and software that can use them) and so on can all be factors and maybe out of reach of most home users' budgets. After you press that key, your software needs to interpret the MIDI signal, look up the appropriate samples or wave forms, apply the envelope matching the keypress, synchronise it with any tracks already recorded, apply any effects like reverb or EQ that's been enabled, perhaps record what just happened, and mix it all together and send it to the sound card, which may have a little processing of its own to do. --71.162.89.207 08:07, 26 November 2006 (UTC)
To answer the original question: Yes, it's true, and the reason has all to do with audio buffer sizes and pretty much nothing at all with MIDI. Cheap sound cards aren't 'slower' than better sound cards (they all have to work in real time), but cheap on-board sound is handled through some OS service (such as DirectSound on Windows), whereas pricier sound cards for more serious applications typically use a special driver that is optimized for low latency (see the article on ASIO, for example). These serious applications (e.g. most virtual musical instruments and all DAWs [meaning Cubase, ProTools etc.], as opposed to MP3 playback or a computer game) let you freely set buffer size, so you can set it as small as you can go without the sound breaking up.
Consider this: when your sound card is running at a sampling rate of 44100 samples per second (CD quality), and you feed audio data to the sound card in chunks of 128 samples (a common buffer size in serious applications), then after handing over one chunk you have less than three milliseconds until that reservoir of data is depleted and the next one is required! Every time a chunk gets to the sound chip late, you get a nasty glitch in the audio. Therefore a garden variety audio solution (with 'audio solution' I mean the combination of sound API, OS, sound driver, sound chip, and all the bits in between) will employ a larger buffer size, which results in higher latency.
As I said, this issue has nothing to do with MIDI per se (MIDI messages travel at light speed, pretty much) and I wouldn't put it in the article. There are more minor latency issues that would be relevant to the topic, once you get the separate issue of audio processing (which the question above refers to) out of the picture, but these are subtle details that would belong in a much more specific article. 86.59.11.23 12:42, 6 November 2007 (UTC)

[edit] MIDI and game port

Following MIDI's official design for DIN-MIDI-on-game-port adaptors on this page and comparing it to this and this pinouts, I'm surprised that MIDI OUT is sent through pin 12 (ground) and MIDI IN is sent through pin 15 (+5 VDC) - what in my opinion means the data is sent to nirvana. Why does it still work? --Abdull 09:22, 26 August 2006 (UTC)

Because the two pages you refer to only deal with joystick applications and pay no attention to MIDI and they both get it wrong by labeling pin 12 as ground and 15 as +5V. No doubt the people who wrote those pages knew that those pins were not ones that any joystick connect to so they measured the voltages with nothing connected, got those values and assumed that's what they were. Such is the accuracy one generally finds in random web articles.... Charlie Richmond 18:17, 26 August 2006 (UTC)
Thanks for your answer. So it's better not to use these diagrams to build your own adaptor as long as you don't want to toast your equipment. --Abdull 11:47, 2 September 2006 (UTC)
Those diagrams give no information whatsoever that is useful for building a joystick-MIDI port adapter since the MIDI connections are neither identified or labeled correctly so there's no way anyone could even start to build such a device using those drawings. Because pins 12 and 15 are actually mislabeled, someone might run into difficulty building a joystick application but it's unlikely anything would be 'toasted'. Charlie Richmond 15:04, 2 September 2006 (UTC)

[edit] Link to mymidishare.com

I removed this external link:

  • Upload and listen to MIDI files for free. but it has been put back again. It seems too commercial and is not adding to the technical side of how MIDI works. Rather than get involved in a pointless editing war, could there be a consensus on whether this link is relevant or not? --Ianmacm 17:45, 29 August 2006 (UTC)
I agree with you completely. Charlie Richmond 18:23, 29 August 2006 (UTC)
  • Agree as well: clearly SPAM. −Woodstone 19:14, 29 August 2006 (UTC)
  • There seem to be other links to MIDI file sites that keep getting put on the page repeatedly as well. Perhaps we could work on a consensus policy that only links about the technical side of MIDI be put on the page and post it informationally at the top. Charlie Richmond 22:21, 3 September 2006 (UTC)

I've added this as a note in the HTML at the top of the external links section: Note: Any links added to this section should contain material about the technical aspects of MIDI. Please do not add links to sites offering MIDI files. --Ianmacm 06:33, 4 September 2006 (UTC)

[edit] External links

I noticed there are a few of redundant sites in this section. I've tried to put some order and I've deleted a few spam sites with no-sense for this topic. I have also added an exaustive link with professional texts by Grove enc. Alegreen 18:24, 16 October 2006 (UTC)

[edit] Midi Compression

Can anyone input some information about how Midi is compressed? Timmah01 02:35, 13 November 2006 (UTC)

MIDI is already inherently extremely compressed, so are you asking how it is done now by definition or how it can be compressed even further? The article basically describes the current method by which a very small amount of MIDI data completely defines very complete musical pieces through a standard language of compressed commands. Charlie Richmond 08:28, 13 November 2006 (UTC)
Actually, MIDI data isn't "inherently extremely compressed" at all, from an information-theoretical point of view. A typical musical performance or score stored in a MIDI file has a fair measure of redundancy, so a utility such as gzip can compress such a file by a much greater factor than, say, an MP3 file (which is already compressed and thus has little redundancy). It's just that MIDI data has a very low bit rate to begin with, so it's practically never compressed because it's just not worth the trouble. The MIDI standard doesn't include anything regarding compression of a sequence of MIDI messages. However, it does include provisions for making such a sequence less redundant in the first place. For example, there is 'running status', which means you can leave out the status byte for a message if it would be the same as the status of the previous message. To make this more effective, you can send a note-on message with a velocity of 0 instead of a note-off message. Thus, when a couple of notes are played (and released) on just one channel and nothing else happens, every single message can have the same status (note-on for the channel in question) and the status byte needs to be sent/stored just once. 86.59.11.23 11:33, 6 November 2007 (UTC)

[edit] History

Maybe someone with a good historical knowledge of midi can create a History section.

[edit] Windows XP users and MIDI playback

OK, I'm a windows XP user, and in the 'control panel' of windows; in the 'sounds and audio devices' icon on the 'audio' tab at the very bottom is a "MIDI music playback" option. Here it gives me a default device to use.

Should there be a section of the article on such integrated devices that are widely used for midi? They are on even modern operating systems. What are those that are commonly found? I for one am trying to look up more information about them and how to load/change to new ones. Search engines like google do little to help and I thought I might find the information here on wikipedia but alas I cannot. Nagelfar 04:51, 7 December 2006 (UTC)

PC sound cards have supported midi playback for a long time because in the early days of PC sound software synthisis would have been either impossible or at least an unacceptable CPU load for things like games. Many sound cards still do and the windows api and control panels for using them are still there. There are also software synths that look to windows like a midi device but really do the synthisis in software and it looks like ms has decided to include one with XP (there are also third party ones but i dunno the names of any off the top of my head). Plugwash 02:14, 8 December 2006 (UTC)


This facility can also be used to redirect midi output to any software or hardware synthesizer. For example if you had a Hardware synthesizer attached to your PC, you could force Windows to use it as your default midi synth, which is what most media players will try to use to playback a midi file. —Preceding unsigned comment added by 68.146.37.30 (talk) 15:17, 26 October 2007 (UTC)

[edit] 'Sound Samples' section is superfluous

How are the drum samples at the end of this page relevant to the topic? They have little to do with midi other than they could potentially be controlled by midi (but so could anything). They are likely to confuse beginers by reinforcing the misconception that midi is sound too. I think they should be removed. Brentt 22:14, 25 February 2007 (UTC)

They seem to be audio recordings of standard MIDI playback on standard MIDI voices. That makes sense to me. --Cheeser1 21:58, 12 October 2007 (UTC)
No! These are .mid files, not audio recordings. Describing them as 'sound samples' is indeed confusing. The section would be relevant to the 'General MIDI' article (if something has 'standard MIDI voices', it's GM; certainly not MIDI itself), but, like Brentt, I don't see the relevance here. If there are editors who would like to keep this material in the article, maybe someone could fix the section by providing an accurate description of what these files actually are and how they relate to the topic? Otherwise I'll remove the section (or I hope someone else will remove it in case I forget); as it is, it doesn't belong here.
For now I'll change the section heading to "Example MIDI files" ("Sound Samples" is simply factually wrong) and remove the "description page" links, as the descriptions themselves have to be corrected (they also state, wrongly, that the files are "sound samples"). 86.59.11.23 11:47, 6 November 2007 (UTC)

[edit] Dave Smith? What about Jim Miller???

Personal Composer, the world's first music/MIDI software for a desktop computer, was written by Jim Miller, who set up for business in his garage in 1983. Jim advanced the DOS-based program, through several releases, to Version 3.3. He was working on a Windows version at the time of his death in 1991. —The preceding unsigned comment was added by 75.71.66.14 (talk) 02:51, 6 March 2007 (UTC).

What is the relevance of MIDI software if there is no MIDI itself? (infindebula - i'm not signed in, 2007/4/25) —The preceding unsigned comment was added by 204.138.85.6 (talk) 13:57, 25 April 2007 (UTC).

[edit] Give credit where it is due...

I understand that Yamaha (associated with Dave Smith) sued Jim Miller for the rights to Personal Composer's software and didn't succeed. I see Dave Smith listed as "the father of MIDI" ... I have done research that informs me that isn't true:

Personal Composer, the world's first music/MIDI software for a desktop computer, was written by Jim Miller, who set up for business in his garage in 1983. Jim advanced the DOS-based program, through several releases, to Version 3.3. He was working on a Windows version at the time of his death in 1991.

Is there anyone who knows about this too or is everybody convinced that DS is "the father" or is this partially BS? —The preceding unsigned comment was added by 75.71.66.14 (talk) 03:01, 6 March 2007 (UTC).


And how do you think one can design sequencing software without the knowledge of underlying messaging protocol and actual electronic musical instruments to connect with? --91.76.189.195 17:35, 2 April 2007 (UTC)
Then Miller is the nephew of MIDI. MIDI predates him. Erudecorp ? * 06:59, 30 October 2007 (UTC)

[edit] Splitting/Archiving

I have split off MIDI usage and applications and The MIDI 1.0 Protocol into separate articles. This has gotten rid of the "this article is getting large" warning. Kc4 17:17, 7 April 2007 (UTC)

I have also archived older discussion threads. Kc4 17:24, 7 April 2007 (UTC)

[edit] Output

On a computer, it's even possible to change what midi music will sound like. What's the term for this (sound font?)? Should it go in this article? Erudecorp ? * 09:51, 30 October 2007 (UTC)

MIDI is a communications protocol, which the article explains. It's not at all concerned with how the audio output will sound. You're probably thinking of General MIDI, which the article mentions. However, I guess the distinction isn't really made clear by the article ... I'm not an expert in this area, so I'm not particularly inclined to attempt to fix this myself, but I have a suggestion for a more daring editor who might want to help clarify the matter: As this is such a common misconception, I'd tackle it right at the top, in the paragraph starting "MIDI does not transmit an audio signal or media ..." and add something to the effect that the same sequence of MIDI messages can be interpreted by synthesizers in many different ways, producing different sounds, and that just from the MIDI messages per se there's no way to tell what exactly you'll hear. 86.59.11.23 12:00, 6 November 2007 (UTC)
Basic concepts and common misconceptions definitely need to be made clearer right in the introduction. Something like this (but in prose):
But then why does .mid redirect to Musical Instrument Digital Interface instead of General MIDI? I'll fix it. Erudecorp ? * 03:18, 4 December 2007 (UTC)
You misunderstood -- a .mid file may be interpreted according to the GM standard for playback, but then again it might not. .mid files you find on the web are generally meant to be played that way, but other .mids can just as well be intended to be interpreted in a different way, e.g. controlling a specific synthesizer at specific settings, or even lighting instead of devices that make sound. But either way, it's supposed to conform to the MIDI standard, thus the original redirect was correct. I've reverted your change. That aside, you're right that better addressing common misconceptions would be great. 86.59.11.23 (talk) 14:39, 29 December 2007 (UTC)

[edit] Merger

I just merged the content of MIDI Composition as suggested. It seemed to fit well within the scope of this page, and I placed it in what I thought was the most appropriate location. I followed the appropriate steps as laid out by Wikipedia. —Preceding unsigned comment added by Deep-fried twinkie (talk • contribs) 16:26, 15 November 2007 (UTC)