Help for Tune Smithy
FAQ - Midi File Save
From Tune Smithy
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, with 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 most 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 for most midi instruments 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, how can I do that?
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 easiest 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.
To take an example, if the music is for keyboard + solo instrument, you could set the solo instrument to play on channel 1 and the keyboard to use all the other channels. Or if you want to avoid the note off pitch shifts, but make sure each instrument is in a separate section of the midi file, you could set the solo instrument to play on say the first three channels, and leave the rest for the keyboard.
Then when you open the midi file you could set up the notation software or whatever you use to display it to merge all the channels for a single part into one display - e.g. in notation software you may be able to overlap the staffs for the first three channels (or whatever it is you need to do).
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.
Okay, so how can I work with unretuned midi source files?
The idea here is that instead of saving a midi file in FTS then editing it in another program, you work the other way. Work with an unretuned midi file in your other program - and whenever you want to listen to it, you play it through FTS. When you want to convert it to audio, then you play it through FTS and record to audio as it plays. Or alternatively, you retune the midi file and then open the retuned midi file to render to audio - but just for the final mix.
With this way of working, you do all the editing with the unretuned source file. So it doesn't matter that the retuned midi file is hard to read as you only use it for the final mix.
For more about this approach, see Tutorials:How use FTS to compose microtonally