I used the pattern sequencer to record a simple drum pattern with a drum kit. But when I press play after I've completed the pattern another part that uses the same keys as the keys I used for the drums is being triggered too.

If you had keyboard control ON for that other part then it was being played and recorded when you recorded the drum pattern.

Then when you press 'play' it plays whatever was recorded - including that other part.

I tried turning off keyboard control for the drum part, but that didn't do anything. I don't have the arp on.

Turn keyboard control OFF for all parts except the drum part. Then play and record the drum part.

I thought all I needed was the keyboard control to be off on the drum part for the other parts to not sound.

Just the opposite - turn keyboard control OFF for the other parts. Then after recording turn keyboard control ON for the other parts but OFF for the drum part. If you play the recording with the drum part keyboard control still ON it will play the drum part, your other parts AND the recording of the drum part.

Hmm, so I guess what you're saying is that when recording it remembers which parts had keyboard control on and then if you turn on keyboard control for those parts and press play, those parts, even if they're not what you intended to record, will play? 

Hmm, so I guess what you're saying is that when recording it remembers which parts had keyboard control on

Not sure I understand what you mean there.

If you play a key on the keyboard then ANY part that has keyboard control ON will play if that key is in the note range for the part and the elements/operators of the part.

1. if part 1 is piano and part 2 is drum

2. both parts have keyboard control ON

3. both parts have a note range of C-2 to G8

4. ANY key you play will play both parts

5. Any recording you make will include both parts

6. If you only want to record drums then turn OFF keyboard control for part 1

7. After recording if you want to both play the recording AND play piano WITH the recording then turn OFF keyboard control for part 2 and turn ON keyboard control for part 1.

You generally have an arpeggio or recording play the drum part so it would normally have keyboard OFF - except you turn it on to do the recording but turn OFF keyboard control for the other parts.

and then if you turn on keyboard control for those parts and press play, those parts, even if they're not what you intended to record, will play?

Why did you say 'then if you turn on keyboard control for those parts'.

1. How many parts do you have?

2. Which parts had keyboard control ON when you recorded?

I have three parts. I had keyboard control on for the first (organ) and third (drums) parts on when I recorded the pattern. I see my error now and it makes sense. 

Great explanation!

Thanks so much.

I have three parts. I had keyboard control on for the first (organ) and third (drums) parts on when I recorded the pattern.

Good to hear you solved your problem.

Now - let's say you want to add a bass part to your pattern so the pattern has drums and bass.

You would turn off keyboard control for the drums since the drums will play with the pattern. So the only part with keyboard control on is BASS. Hit record and then play and play the bass part while the pattern plays the drum part.

Now you have both drums and bass in the pattern so for normal use you would turn keyboard control off for both of those parts while you play the pattern, the organ and any other parts.

Your pattern can be multi-track. Blake has a great article and tutorial on doing just that:

https://yamahasynth.com/learn/modx-series-synthesizers/mastering-modx-pattern-workflow-and-control-improvements-in-os-v2-5/

While it is fresh in your mind I suggest you actually try the tutorial example while you read how Blake does it.

Turning keyboard control OFF for a given Part means that the given Part won't receive MIDI (note on/off/controller/etc) events unless that Part is selected (only one Part can be selected at a time).

If you have keyboard control OFF and you select a Part then that single Part will receive all of the events and no other Part will. 

The only way to send MIDI events to more than one Part at a time (using the local control surface) - is to turn keyboard control ON for multiple Parts and also either select one of the keyboard control ON Parts or select no Parts.   One way to select no Parts is to press the [PERFORMANCE] (HOME) button or touch the Performance name in the home screen or press the [COMMON] button (Montage only - MODX saves some buttons vs. the flagship).   Either way you do this by selecting a keyboard control ON Part or selecting no Part -- you will be NOT selecting a keyboard control=OFF Part.

And when you are not selecting a keyboard control=OFF Part, all of the Parts with keyboard control turned ON will receive MIDI and controller events.

All of this applies to the Pattern Sequencer as well.  All of the "rules" above still apply.  Now you have choices of how to get the job done.

If you want to record a pattern that only targets Drums (say Part 4=Drums just for example) then you can either

1) Turn ALL Parts Keyboard Control OFF.  Then select Part 4 (the Drum Part) and start recording.  Only the selected Part will record MIDI data.  If you want to loop around and record another Part exclusively then you can just select that other Part and since its keyboard control is OFF - all of the MIDI events will be sent to just that single Part you selected.   For me this workflow works perfectly assuming all Parts are single-Part instruments.

--or--

2) Turn keyboard control ON for only the Part(s) you want to send MIDI data to and then either select NO Part or select any of the keyboard control=ON Parts.  The downside of this approach is that there's more to manage in terms of setup.  The advantage is clear for Multi-Part instruments.  Some pianos, for instance, will take 3 Parts to realize the entire instrument.  You'd want to turn ON Keyboard control for all 3 of those Parts (and OFF for all other Parts) if you wanted to record the Piano as a unit and have the instrument in tact.  

After you record this, however you do it (correctly) there won't be any messages targeting any other Part(s) except for the ones you told the Pattern Sequencer to record.  Even if you had every Part's keyboard control ON during playback you would not hear any of those other Parts getting triggered.

Your answers were extremely helpful. Thank you both!