Play PianoFlex in REAPER

PianoFlex comes as a VST3 plugin as well as a program, so you can play it on a track in REAPER, record what you play, and mix it with the rest of your song. This page takes you from a fresh install to a recorded piano part.

1. Install the plugin

Run the PianoFlex setup and leave the plugin ticked. It goes into C:\Program Files\Common Files\VST3, the folder REAPER and most other music programs search for VST3 plugins.

2. Let REAPER find it

REAPER usually finds new plugins when it starts. If PianoFlex isn't in its list:

1. Open Options > Preferences, then Plug-ins > VST. 2. Check that C:\Program Files\Common Files\VST3 is in the list of VST plugin paths. 3. Click Re-scan.

3. Put PianoFlex on a track

1. Choose Insert > Virtual instrument on new track…. 2. In the list, type PianoFlex in the filter box. It's listed as an instrument from Flex Music Labs. 3. Double-click it. REAPER makes a new track with PianoFlex on it and opens PianoFlex's window. If the window doesn't open, click the track's FX button.

The window is the same as the PianoFlex program's, with the same presets and sliders. A few parts are missing because REAPER does their job: MIDI in, the sound output, the delay, opening and rendering MIDI files, Record and MIDI out.

4. Play it from your keyboard

The new track is already armed for recording, with monitoring on, so don't click its record-arm button (the round red one): that would disarm it.

1. Right-click the record-arm button, choose Input: MIDI, then your keyboard, then All channels. 2. To check that you'll hear what you play, right-click the record-arm button again: Monitor Input is ticked.

Play a few notes. The keys light up in PianoFlex's window, and the sustain, sostenuto and soft pedals work from your keyboard.

If your keyboard feels too soft or too loud, set its curve in PianoFlex's Velocity Curve panel. See Fit PianoFlex to your keyboard. In the plugin, the curve is saved with your project.

5. Choose a piano

Click the preset name at the top of PianoFlex's window and pick a piano. Session Player is the one PianoFlex starts with. Or build your own sound from the Piano, Style and Space lists.

6. Record

Press REAPER's record button and play. REAPER records the MIDI notes, not the sound, so you can still change the preset afterwards and the part plays back on the new piano.

7. Save, and come back later

When you save the project, REAPER stores PianoFlex's sound with it: every slot that's on, its sound and layer settings, and the room the layers play in. Open the project again and the piano sounds as you left it.

The volume you set in PianoFlex's window is saved with the project too. Solo and mute (S and M on the slots) aren't: they come back off.

Good to know

• Level: a new plugin starts at 0 dB, a level that sits well with other instruments. A safety limiter keeps the loudest chords just under the top. Ordinary playing passes through it untouched.
• Your own presets are shared between the plugin and the PianoFlex program.
• Making an audio file: use REAPER's File > Render.
• Layers: turn on more than one slot (A to D) to play pianos together. See Layers.

More: all the Learn guides and the PianoFlex user guide.