Tonight is the first time I noticed the absence of the old per-track arp in SPlat. It was in the Pro Channel in previous versions.
 
Am I missing something?
 
Thanks!
 

Press MIDI at the bottom of the prochannel window, then you can see the arpeggiator

MIDI at the bottom of ProChannel ???  - [EDIT: Ahh I see - MIDI tab at the bottom of the Inspector (when a MIDI or Instrument Track is 'in focus').]
O in image - Doccy. / More Doccy.

 (Many ways to do things) 
Alternatively: 
It's a MIDI FX (effect) which can be added as to MIDI clip:
e.g,
- from Browser > Plugins > MIDI FX > Arpeggiator ... drag/dop
- by right-clicking the clip Process([Insert]) FX > MIDI FX > Cakewalk FX > Arpeggiator
- drag/drop or right-click insert into Inspector > Clip > Clip FX
 
Doccy

Thank you!
 
I see it now. I think my SPlat was a little ill last night. The right side of the PC was blank. Weird. But it's fine now.
 
Thanks again!

I just cross-updated my above post if ya missed it. Take another look :)
 
PS - Thanks Roger ... I've not played with that method before - interesting - Latch etc :)

There's also these very interesting arp preset patterns (Alesion_ARP) that were done a long time ago, but are still very useful and can be easily accessed via the Inspector Pane....under Presets. (Not sure if the download link is still working....I believe it's the Alesion PTN Construction Kit.  
 
(edited for technical correctness)

Just an FYI...technically speaking, the pane that's usually on the left is called the Inspector. One of its tabs is the ProChannel. Of course it's not a big deal, but if we call the same thing by different names it could lead to confusion.

Yup:
 
Skylight:

A. Control Bar
B. Inspector
C. Track pane
D. Clips pane
E. Video Thumbnail pane
F. Browser
G. MultiDock (showing a Piano Roll View, Console behind in first tab).