Hello, Dale:
I don't know True Pianos specifically, but the first thing you need is a "virtual midi port". These reroute midi signals sent from Notation back to other software running on your computer.
There are several alternatives but your choice may depend on what operating system you're using.
I use the Maplemidi with XP, but it has known issues with Vista -- I haven't heard anything about it and Windows 7. And even more to the point, the developer has stopped development on it. An archive of it can be found here:
http://www.postpiano.com/Maple/maple-index.htm
There are also these alternatives, but I don't know anything about them and their compatibility with current operating systems:
LoopBe1 --
http://www.nerds.de/
MIDI Yoke --
http://www.midiox.com/ (
http://www.midiox.com/)
MIDI Connection Center 1.1 --
http://www.musiclab.com/downloads/free/
If True Pianos is a "stand alone" program (ie., comes as an .exe file), then you're good to go. If it's a VSTi or DXi (ie., comes as a .dll file), then you need a host. Herman Seib's SaviHost is the go-to solution for VSTi's (
http://www.hermanseib.com). I don't know of any DXi hosts other than within sequencer programs, such as Power Tracks Pro.
Here's the process:
1: Install the virtual port(s). Reboot. The virtual port(s) should now show up as midi port(s) on your computer.
2: Install and run the host (if needed).
3: Run True Pianos in the host (if needed).
4: Point the host's midi in device to a virtual port -- or True Piano's midi in, if it is a stand-alone.
5: Run Notation (Composer/Musician/Player) and point the midi output the tracks you want sent to True Piano to the same virtual port you selected for True Piano.
6: Play the file -- it should work.
Important note: always run True Piano or its host FIRST and make sure that its input port is set to the one you want. THEN run Notation. Otherwise you'll get very erratic behaviour and a potential system hang.
Good luck.
David