I used to own a MOTIF (gone now) -- and I really miss the great Drum Patterns it had. Truly inspirational.
I imagine the stuff they developed for Montage is equally good.... and probably even more of it.

--> Is there a source anywhere for the Durm MIDI Yamaha developed for these great workstations?
(MOTIF and/or MONTAGE) -- to Buy or what-have-you?

I only work in DAW (Cubase) with MIDI keyboard now.

Welcome back, and welcome to YamahaSynth!

The evolution of the Motif-series to the current models MODX/MONTAGE has been one worthy of notice. There are still two sequencer modes: one linear (“MIDI Song) and one loop based (Pattern). Both can be used together to create your own custom data.

This means not only can you record your own drum grooves from scratch, but you have several methods of assembling data from other sources (via .mid file format). There are over 3400 drum grooves in the factory Arpeggio Phrase data. Then realize that any MIDI file (.mid) containing Drums can be loaded and you grab any portion of that data to construct your own custom drums tracks.

You have “Divide Drum Track”, that lets you sort and separate drums, so you can customize the sounds and build custom Kits; grabbing what you like from the available data. You can use the data as is, or extract the components you find interesting.
You have advanced “Arp play FX” and “Track Play FX” which allow you swing, requantize, note shift, and otherwise transform the phrase data.

For example, you can load any MIDI File to the linear MIDI “Song” sequencer.
Then using the Pattern Sequencer, you can ‘grab’ any range of measures and turn them into new Drum Patterns.
Doing this kind of assembly/reassembly makes almost any MIDI drum data available to you as source material.

Yamaha Synths come with a freebie copy of Cubase AI. If you have not yet discovered the VST plugin “Groove Agent”, it is well worth the time investment to add this to your toolkit. There is a Steinberg YouTube Channel and tons of video tutorials that can introduce you to Groove Agent — you’ll find it a compelling way to put together drum tracks that ‘breathe’ and come alive, rather than just remain steady to the point of becoming too steady. Groove Agent is really great as a rhythm tool available to use with or along side your MODX/MONTAGE.