Dr. Shark asked me this question by private email, but I thought I'd post my answer here for everyone...
He asked-"How do I access the melodic sounds in my Roland TD-20 from the Zendrum?"
The drum channel is usually MIDI channel 10.
That's the default in the Zendrum factory presets.
When I test and ship ZX Zendrums here at Zendrum World HQ, I always send them on Set Up 15.
That's the General MIDI map for drums that most resembles my personal trigger layout and illustrates how I'm getting away with not using my feet at all. It will have three bass drum note triggers #36, four snare drum triggers, and a couple of doubled up toms. As primarily a drumset playing musician, this makes the most sense (to me). It's just a starting point that you can edit anyway, but at least gets you going in the first five minutes after the Zendrum arrives with most hardware and software without having to program anything right away. Of course you are encouraged to "make it your own", and nobody plays exactly the same as me, not even my partner Kim. Just as there is no "right way" to set up an acoustic drum set, the same applies here. That's cool. If you are playing drumset, you want everything to stay in the same relative position, even when you change the sound of the kit.
The other 15 memory banks, or Set Ups- (UP) display are really only there because people started using the Zendrum to play melody. Bass, Piano, Vibes, tuned percussion, etc. This turns the Zendrum into something else entirely. "The Mayor" Tom Roady did a whole CD years ago where everything on it was recorded using Zendrum for melodic sounds as well as drums and percussion. Very cool.
So here's what you do to play piano from the TD-20-
Pick a Set UP that you don't use for drums, say #1.
That's a C Major scale as the default.
Bear in mind the notes can be edited to match whatever music you are performing.
1) Left cursor to UP screen
2) Press + to show the current # Set Up
3) Change to #1 by pressing -
4) Press right cursor to CH screen
5) Press - to change channel from 10 to 1
6) check sound: this should be a melodic note now
7) left cursor to Pr screen
Pick sound by pressing + or -. (Piano is Program 0 or 1 for instance)
9) Left or right to show letters not numbers to write into that Set UP's memory.
If your Zendrum is rev. 31, you can also toggle between the Set UP numbers and only send note map changes without sending the other parameters. This feature allows for chord changes within a piece of music. Best results will be if you also toggle the sustain switch polarity (PL) screen from 0 to 1. Then the Zendrum's momentary switch or any external sustain pedal acts as a "kill" to cut off the ringing notes after it's pushed once.
Hope this helps,