Thank you thank you, John.

Nelson, you're most welcome.

Like I said, I did all the research I could think of including checking Rodgers i548's manual online. Here 'tis
https://frogmusic.com/owners-manuals/538i548.pdf

It shows the channels as
1 Manual I
2 Manual II
3 Pedal

But they've shown as 12, 13 and 14 in Sonar tracks since I started. They've wandered oddly since I tried doing some sequencing for this organ at home on Casio and Korg keyboards, but hopefully that won't affect the present discussion.
Sekaiju could edit Sonar files -- I could crack into them at last? Have downloaded the installer but don't see an .exe to click (except for a "MAINFIEST File"), possibly because my free trial of Winrar expired long ago. It give sme popup reminders at times like this.
So you're a Sonar 7 person -- boffo! What do you mainly do with it? Any idea how PE is different from the SE?

Thanks, I downloaded the manual. (Quite a nice piece of kit you have there.) 😉

No, you didn't READ the manual. It says it transmits on 1,2 and 3 but can be set to transmit on various other MIDI channels.
This is if you have an external MIDI sound module providing orchestral voices, for example.

But it records on 12, 13 and 14 (see Global MIDI settings) and responds to incoming MIDI messages on those channels. (Makes sense.)
(This from one very quick scan through, so I'm not sure if it's completely accurate, but it seems to be how Rodgers implement most of their organs, from having a quick glance at other manuals.)
So stick with channels 12, 13 and 14 (upper manual, lower, pedal) for all the MIDI files you prepare.

Sekaiju is a very straightforward sequencer, it just deals with MIDI files. To unpack Sekaiju try using 7-zip file manager.

The other very good sequencer is Anvil Studio. The basic program is another freebie. There are several, paid for, packages that add functionality.

I still use an antique program called XGworks, from Yamaha, to do most of the MIDI sequencing on, only migrating to Sonar for rendering to audio.
I make orchestral backing tracks for my wife, an operatic soprano, to rehearse or sometimes to use in recital.
Sonar PE just adds a whole raft of add ons (as far as I know) to the standard Sonar 7 program.

Regards,
JohnG.

Thanks, I downloaded the manual. (Quite a nice piece of kit you have there.) 😉

No, you didn't READ the manual. It says it transmits on 1,2 and 3 but can be set to transmit on various other MIDI channels.
This is if you have an external MIDI sound module providing orchestral voices, for example.

You're most kind to do all that research. Interesting! Glad you like our toy -- my final/current assessment and the whole saga here
https://organforum.com/forums/forum/electronic-organs-midi/classic-church-electronic-organs/9555-help-urgent-my-church-s-dilemma?9226-Help!-Urgent!-My-church-s-dilemma=

You have a musical wife to collaborate with -- how marvelous! Could you explain rendering a MIDI track to audio within Sonar? Supposed to be easy but another total failure for me. (As ever, tried the Help section in addition to googling.)