Skip to main content ↑ ↓
Topic: MPC help needed (Read 4978 times) previous topic - next topic

MPC help needed

I am having difficulty in getting my head round the MPC settings especially the 'Sweep Resolution' entry. What does this actually define ? I am sequencing an arrangement for Theatre Organ using NWC and jOrgan where the Swell controls (aka Shades) are almost continually on the move and there are many quite complex MPC controls. I just can't get predictable or sensible results. Several times I have thought I had cracked it. Only to find that it doesn't work when I apply my hoped for insight. I have read everything I can find on this but remain none the wiser.

What is mising is a proper understanding of what the MPC controls actually control and do. Their names offer little help and the description of the Sweep Resolution control in the paper in the Scriptorium is, at least to me, totally opaque.

Some help would be appreciated.

Bruce Miles

Re: MPC help needed

Reply #2 –
Quote from: Bruce Miles –
I am having difficulty in getting my head round the MPC settings especially the 'Sweep Resolution' entry. What does this actually define ?
Perhaps the Linear Sweep Contour section of the Multi-point Controller Command will help. A higher Linear Sweep Contour will cause fewer MIDI messages to be generated at the expense of the smoothness of the sweep. The tradeoff is sometimes needed because some synths are overwhelmed by too many MIDI messages per second and behave badly.
Registered user since 1996

Re: MPC help needed

Reply #3 –
Thanks for those replies. Some understanding is beginning to break through although the actual identity of the parameter (ie the number to put in the Sweep Resolution box) remains obscure.

In any case it would seem that this figure applies to all the transitions in an MPC box. These (up to 3 or 4) transtions will probably be at completey different rates varying from a sforzando type volume increase of say from pp to ff (100) in an eighth note period to a slow and small increase from mp to mf (25) over several bars. One setting cannot possibly be suitable for all.

One solution would be to use a separate MPC for each transition (when a 'right' Sweep Resolution figure to enter is found).

Later today I intend try the Crescendo/Diminuendo (hairpins) alongside the equivalent MPC controls and compare the results. There are two swell boxes using midi volume control on two different channels - this BTW is addition to other controls using the foot and effects controllers.

Bruce Miles

Re: MPC help needed

Reply #4 –
There's a very big difference between the MIDI velocity modulation (hairpins) and the volume or expression MPC.
The hairpins change the velocity (i.e. the "strength") at which the "key" is pressed; they have an audible effect only if the hairpin encompasses a run length of notes, in this case each note has a different velocity.
N.B. A different velocity can also imply a different timbre.
The MPC linear sweep works in time; you can change the volume/expression of an already playing note.
N.B. Only the volume is affected, not the timbre.

The Sweep Resolution depends on the width and duration (in real time, not just the tempo) of the transition and possibly on the desired smoothness. You have a range of useful values for each case, but you can't have a "one size fits all". This is even more true for the pitch bend MPC.

Re: MPC help needed

Reply #5 –
In my setup NWC is feeding its midi messages to a virtual organ console in jOrgan and the controls on the organ screen (keyboard notes, stop knobs or tabs, swell box pedals etc)) move accordingly. The notes play and the sound responds to the controls. The swell pedals are set up to respond to controller 7 and they do move and respond in exactly the same way whether I am using MPCs and Linear Sweeps or discrete 'Dynamic' entries and hairpins.
I seems to me that the Dynamics and hairpins are just a graphic interface for the MPCs. The Dynamics can only control volume, but MPCs can control anything.
I don't think I can say I'm certain of all this yet. I was hoping to be able to record the actual midi messages NWC is producing but I haven't got round to it yet.
I am staying clear of the midi velocity minefield - it is just not relevant to organ music. It only concerns instruments whose tonality can change as they are played. (There - I've really stuck my neck out on that one)
This disagrees with most of what Flurmy has said - sorry about that but it's how things seem to me.

Bruce Miles

Re: MPC help needed

Reply #6 –
Quote from: Bruce Miles –
I am staying clear of the midi velocity minefield - it is just not relevant to organ music. It only concerns instruments whose tonality can change as they are played. (There - I've really stuck my neck out on that one)
This disagrees with most of what Flurmy has said - sorry about that but it's how things seem to me.
Bruce Miles

I don't think you're disagreeing with Flurmy - he was just commenting in general, for instruments which have a "velocity", such as a piano. Pressing a piano key quickly vs. slowly gives a different tone, but you're correct about organ music. Other than a little extra "air" noise as you are pressing the key (on a pipe organ) there won't be any difference in a fast vs. slow key press.
Edit: I re-read Flurmy's message, and now I think I see what you are disagreeing with. In NWC properties, dynamics (p, pp, mf, etc.) have a velocity associated with them, but they can also have an optional volume change expression. However, inserting a dynamic will also change the volume for instruments that don't have velocity, such as an organ, so they must be specifying both the velocity and volume during playback.

Mike
 

Re: MPC help needed

Reply #7 –
Quote from: Bruce Miles –
I am staying clear of the midi velocity minefield - it is just not relevant to organ music.
I agree, but be aware that NoteWorthy uses MIDI velocity for accent and marcato.

Quote from: Bruce Miles –
I seems to me that the Dynamics and hairpins are just a graphic interface for the MPCs. The Dynamics can only control volume, but MPCs can control anything.
Dynamics control velocity. Dynamics can be configured to control volume. I use volume to control channel mix so I seldom configure Dynamics to control volume.

MPC's cannot change velocity.

Good luck with your project. It takes discipline to limit use of MIDI only to that which makes sense for the instrument being emulated.
Quote from: Mike Shawaluk –
Other than a little extra "air" noise as you are pressing the key (on a pipe organ) there won't be any difference in a fast vs. slow key press.
Are you sure about that? I would generally expect no difference for a pipe organ. Bruce says that he is trying to emulate a theatre organ. Theatre organs are beasts. For many stops, you don't know what you get until you try them.
Registered user since 1996

Re: MPC help needed

Reply #9 –
Quote from: Rick G. –
Are you sure about that? I would generally expect no difference for a pipe organ. Bruce says that he is trying to emulate a theatre organ. Theatre organs are beasts. For many stops, you don't know what you get until you try them.

I was thinking of the case of someone trying to "emulate" a pipe organ on a velocity sensitive keyboard. I'd imagine if one plays an actual pipe organ (which I have never done) and presses a key slowly, there might be a softer beginning to the note because the air pressure changing as the key valve opens, versus pressing the key down quickly. But this was more of a musing on my part.

I don't know much about theater organs either, but Wikipedia says that they tend to be pipe organs.

Mike

Re: MPC help needed

Reply #10 –
Quote from: Mike Shawaluk –
I don't know much about theater organs either, but Wikipedia says that they tend to be pipe organs.
They are much more than pipe organs. Some stops are dedicated to sound effects, others to percussion.
Registered user since 1996

Re: MPC help needed

Reply #11 –
I don't know if this will help, but one difference to keep in mind between velocity and volume is that velocity controls individual notes, while volume controls the entire MIDI channel. Dynamics in NWC control velocity instead of volume in order to avoid problems where one might want different dynamics simultaneously in the same channel.

An example: for a piano score, I usually put both staves on the same channel. This allows pedal marks on the lower staff to also affect the upper staff, and for slurs that extend across staves without breaking between channels. But there are plenty of times when I want the two hands to be playing at different dynamic levels. Using velocity for dynamics allows this. Using volume would not: if both staves are on the same channel, both have to be playing at the same volume.

For organ music, of course, you would want to use different channels for each manual and for the pedal board, to allow each one to use different stops. But the principle holds.

Re: MPC help needed

Reply #12 –
MIDI has a velocity value for each note, That's a matter of fact.
If your synth makes use (and which kind of use) of it is up to him.
And sometimes the keyboard allows you to fix it at a predefined level.
I often found the synthetized pipe organs having dynamics keyboards...

Then MIDI has volume and expression real time controls.
What that implies is already clearly explained by Bill.

That's MIDI.

As Rick said, NWC in the "advanced settings" lets you use the dinamic indication to specify both the velocity and the channel volume (see Bill). Feel free to use it, but take care of all the side effects.

Mike, many new pipe organs have an electronic console. This allows the console to be moved and placed where it is preferred. As far as I know, the keyboard messages are simply key on/key off so, at least in this case, it really doesn't matter how fast the key is pressed. The same goes for many, if not all, the electronic organs, Hammonds included.

Re: MPC help needed

Reply #13 –
I must confess I overlooked the options to set the Dynamic setting to control either Volume or Velocity or both.

So as a follow up to my original question and looking again at the way my Swell shutters perform, it seems that the dynamic + hairpins controls function in the same way as the MPC box etc does provided they are set to control the same things - velocity and/or volume. Regarding the Sweep Resolution setting, everything functions OK using MPCs with this set to the default 1, so it seems that this figure fits all, at least in this kind of application.

Thanks for all the replies. I've learned a lot from this discussion.

My emulation is indeed for an electric action theatre  organ where the response to key pressure is fixed . That is - leaving out the second-touch feature but that's another story.

Bruce Miles