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FAQ - Midi File Save

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What is the distinction between type 0, type 1 and type 2 midi files?

This can cause confusion because of the distinction between channels and tracks in Midi. What many programs (e.g. Sonar) present as Tracks in the user interface correspond to Midi File Channels.

Each Midi Track can contain nidi events for all the 16 Midi Channels. The tracks in the midi file just correspond to the way the events are organised in the file, which isn't normally presented in the user interface.

In format 0 Midi files, all the midi events are in one section of the file so the file has one "track". In format 1 midi files then tempo events are stored in a different section of the file so it has 2 "tracks", the track with the musical notes, and the tempo track. In format 2 Midi files then you can have any number of tracks each with up to 16 channels in it and in effect is really a way of archiving several midi files into one larger file - format 2 Midi files are rare.

When I open a midi file saved in Tune Smithy then I see the notes for a single instrument (Part) spread out over many channels - why is that?

This is to do with the way pitch bends work in Midi

Each midi Channel can have only one pitch bend. That's because the pitch bend wheel adjusts all the notes in play in the same channel at once - try adjusting the pitch bend wheel on your keyboard, set to play on a single midi channel - and you will find that all the notes move in pitch by the same amount.

So if a part has two notes in it played simultaneously, and a different pitch bend is needed for each one, then the notes need to be played on different midi channels - even if they are for the same Part in Tune Smithy.

An example may help make this clear

If you play for instance a just intonation major third in Tune Smithy, say C and E, this will require midi note 60 with no pitch bend for the C and midi note 64 with a downward pitch bend of -14 cents for the E. Since each channel can have only one pitch bend in play at a time, then these notes need to be played on separate midi channels.

The notes need to be spread over many channels even for a part without chords

Even if the part has no chords and is basically monophonic - still the notes often may overlap a little - since midi instruments often continue to sound quietly for a while after you release the key. This is particularly noticeable for some midi instruments, for instance many implementations of the midi Orchestral Harp sound for a fair while after the note off. But nearly all notes continue to sound at least momentarily. It's not that noticeable until you hear what it sounds like if this doesn't happen. If the note stopped at the exact instant when you released the key it would sound strange as if the sound had suddenly got cut off, not like a normal note off.

So - if you play all the notes in the same channel, the previous note would continue to sound momentarily at least into the pitch bend for the next note. This creates a strange pitch gliding "echo" effect after every note played.

To avoid this, normally Tune Smithy spreads the notes over many channels even in this case, even for monophonic music.

I understand that - but still want the notes to be played all on the same channel

In some situations then you may not mind about the (fairly subtle) note off pitch shifts, indeed with some instruments they may be very quiet or not heard at all. You may find it easier to work with the midi file if the notes are all on the same channel.

The east way to do that is to go to Midi Output Channels for Parts and Polyphony (Ctrl + 60) and use the Chann = Part button. This will set each part to play on a single channel.

Note though that this will mean that because of the midi pitch bend restrictions - none of the parts can play polyphonic music - unless all the intervals in the chords are twelve equal intervals.

What can I do if I need some of the parts to play chords as well?

If you want one of the parts to play polyphonic music with non twelve equal chords, you must assign several channels to that part. For instance if a part plays four part chords, it must be given at least four channels to play on - preferably more.

However even with polyphonic parts, if the music is reasonably straightforward in terms of the number of instruments, i.e. a small band or chamber music rather than orchestral, you can probably set up the channels for the parts so that each part has its own set of channels to use all to itself. This approach can make the midi file created much easier to read in other programs.

Is there any way around this - I want to be able to work with midi files without this restriction

Yes - two ways around it. One approach is to use midi tuning tables. But only a few synths and soft synths recognise those.

The other approach though, and normally the best way to compose with midi files using Tune Smithy is to work with unretuned midi source files rather than with the files output from Tune Smithy.

Working with unretuned midi source files

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