LPX Question about MIDI CC's in different views [SOLVED]

There seems to be a distinction of some kind between MIDI CC's depending on where they come from.

If I use MIDI Draw from the Piano Roll to enter 3 CC 11 nodes, I see 3 nodes in MIDI Draw. I see 3 events in the event list. But, I see many more "somethings" in the Step Editor.

Fig. 1

If I turn on "Additional Info" in the Event list, I see more controllers - like Step Edit, not the number of nodes in the Piano Roll

Fig. 2

If I turn off "Controllers" in the Event list, all controllers go away.

Fig. 3

What is the status of these CC's that are only displayed when "Additional Info" is selected?

The sound is that of many controllers regardless of what is displayed.

drb

What you're seeing is that Logic hides some of the MIDI events when "Additional Info" is deselected, and shows them all when it is selected.

First, understand that there's no such thing as a "Continuous Controller" in the MIDI standard: MIDI is a language made of events, and for every knob, wheel or fader you move, there's only a finite number of events that is being transmitted. So when you move the mod wheel from values 1 through 6, it will actually send 6 individual events: 1, 2, 3, 4, 5 and 6. So it's really stepping through those 6 values, and not continuously moving between 1 and 6.

Now "MIDI Draw" is a technique used to draw a bunch of events quickly. It allows you to enter nodes that each have their own values, and to display a line joining the two nodes. So all you see are the values 1 and 6 and a straight line in between. In the Event List, with Additional Info deselected, it only shows you the values 1 and 6. But under the hood, when drawing those two nodes in MIDI Draw, Logic creates all the necessary in between MIDI events to give the illusion of a continuous movement. It creates events with values of 2, 3, 4 and 5 and places them at specific positions to recreate the perception of moving from 1 through 6 according to the line drawn in MIDI Draw.

Those are the "under the hood" events you see when selecting Additional Info in the event list.

The "extra" events are not extra at all. As David explained, they're generated by Logic. It's just that sometimes they're visible, sometimes they're not. But whether Logic generates them has to do with how far apart the nodes you draw in are spaced.

If you wanted, say, a sudden CC#11 jump from a value of 0 (silence) to a value of 127 (max), you would have to draw a node at a value of zero and then another one at 127. But you would have to position the one at 127 extremely close to the one at zero to prevent Logic from automatically generating intermediate values between 0 and 127. EXAMPLE: if the value of zero is at 1 1 1 1, position the value of 127 one tick later, at 1 1 1 2. Try it and you'll see.

What ski said. Example (ski, you posted before I had a chance to take the screenshot, now I don't have to explain how I did it.. ):

That's an even better example (a picture is worth 1000000 words) where you start off "establishing" an area of "off" (makes things easier) and then boom, you draw a node one tick later that bangs the value up.

David and Ski, thanks for your replies.

After reading your replies and doing some experimenting, the following seems to be the case to me:

1. The only case where not all CC's are shown is in a MIDI Draw window when CC's were entered with MIDI Draw and the particular CC is not one defined as on/off. (MIDI draw represents sustain, for example, as a step function with no extra nodes.) CC's entered by other means always appear in all (appropriate) windows.

2. For the case in 1. , generated CC's can be seen in the Event List with additional info, the Step Edit window, or the Track window (with either automation turned on or MIDI Draw turned off).

Is this correct?

drb

What I want to add is that when it comes to the MIDI spec there are no CC's that are defined "on/off" only. In fact, the function that any particular CC is characterized with ("MIDI Volume" or "Expression") are not mandates of the spec but suggestions. Fortunately, most MIDI manufacturers and developers have followed them, for the most part.

And then there is the matter of how things might be implemented in a DAW: there is a range of CC's which are designated as "switch controllers" such as sustain pedal, portamento, sostenuto, etc. but there's nothing in the MIDI spec that specifies or requires them to be limited to on and off states exclusively. In fact, they're all defined as having ranges from 0 - 127 just like so-called "continuous controllers" such as modwheel.

However, in Logic, the developer decided that CC64 should be handled differently than other CC's, even other "switch controllers", in terms of how you can enter data for them. As you discovered, if you try to draw in a linear curve with CC64 in MIDI Draw, you can't. The values step. However, that's not the case with CC65, another "switch controller".

So the handling of CC64 is purely a Logic thing, and not a specification of MIDI.

[EDIT: added pictures from (gasp!) Logic 9. Top, linear curve for CC11 easily drawn in with pencil tool. Below, attempt to draw in a curve of any kind with CC64.]

1. The only case where not all CC's are shown is in a MIDI Draw window when CC's were entered with MIDI Draw and the particular CC is not one defined as on/off. (MIDI draw represents sustain, for example, as a step function with no extra nodes.) CC's entered by other means always appear in all (appropriate) windows.

In other words,

The only case where not all CCs are shown is when you see a curved or slopped line between two nodes: in that case the Event List hides the events Logic had to create in order to follow the shape of that line and only shows the events corresponding to the two nodes you created.

2. For the case in 1. , generated CC's can be seen in the Event List with additional info, the Step Edit window, or the Track window (with either automation turned on or MIDI Draw turned off).

Any MIDI event can be seen in any MIDI editor. But each MIDI editor has its own way to display events. For example to see MIDI notes in the Step editor you'd have to either switch to a specific lane set or create a new lane set containing that event. To see CC in the Tracks area you have to turn on MIDI Draw. And to see in-between node events in the Event list you have to click Additional Info.

Hm, my copy of the MIDI spec (ordered from MMA) says 64 - 69 are normally switches. Like any and all MIDI messages, they can be used otherwise. (Garritan Personal Orchestra keyswitches are not in the MMA MIDI spec , for example).

Anyway thanks for your answers, I accidentally was comparing the sound of a pedal on a sustain instrument in GPO with what GPO calls auto legato, CC 102 used as a switch. These two looked different with nearly the same data and surprised/confused me.

I think I understand what's going now.

Thanks,

drb

Like I said, 64 - 69 have the (loose) designation of being "switch controllers" but they are not restricted to being to used as though they have only two possible states (0,127). Similarly, any "continuous" CC can be implemented as a switch, such as CC102 in your example. If you read the spec closely you'll see that implementation is not cast in stone for Channel Voice messages.

There are exceptions for CC's 120 - 127, which are and should be treated as reserved.

Keyswitches are just MIDI notes so they don't need a specific designation in the spec. It's purely a matter of implementation. Lighting controllers and mixer-style control surfaces typically transmit and receive CC64, pitch bend, and note messages in relation to movements of faders, pots, and switches.

Ski, I think we are simply wording the same thing slightly differently. I am not disagreeing with you. My apologies for not being clear.

Thanks,

drb

No problem here, just clarifying things myself. With words. Maybe even too many. Drinking a new brand of coffee that's got quite a kick!