Where the sound goes

ComposerFlex writes the music, but it doesn't make any sound by itself. A piano plays the notes. Output, at the top of the window, chooses where the notes go. If you change it, the change takes effect the next time you click Start.

PianoFlex (OSC), the usual setting

With Output set to PianoFlex (OSC), the notes go straight to a piano on the same PC. (OSC is the way ComposerFlex and the pianos talk to each other inside the PC; nothing goes out to the internet.) There's nothing to connect or set up. The piano can be either of these:

• PianoFlex Player comes with ComposerFlex. It's one fine grand piano, and you can choose the room it plays in.
• PianoFlex, if you have it, gives you every one of its presets, and you can change the piano and its sound while the song plays.

When you click Start, ComposerFlex looks for a piano that's already running:

1. If PianoFlex is running, the song plays on PianoFlex.
2. If PianoFlex Player is running, the song plays on PianoFlex Player.
3. If neither is running, ComposerFlex starts PianoFlex Player for you. (If PianoFlex Player isn't installed but PianoFlex is, it starts PianoFlex.)

The Output control then shows which piano is playing.

MIDI port

With Output set to MIDI port, the notes go out as ordinary MIDI, to your own instrument: a keyboard or synthesizer connected to the PC, or another program.

1. Set Output to MIDI port.
2. Click the box beside MIDI port, left of MIDI archive. It shows the port's name, or None. A list shows everything on your PC that can take MIDI right now: an instrument you've connected, a MIDI interface or a virtual MIDI port, each under its own name.
3. Choose one, then click Start.

ComposerFlex remembers the port you chose. With Output set to MIDI port, the song plays only on that port, never anywhere else. If no port is chosen, or the port isn't connected, nothing plays, and the yellow line says why and what to do: choose a port, or connect the one you chose. If the port is there but can't be opened, another program may be using it: the yellow line says so, and nothing plays.

If the yellow line says "This PC has no MIDI output ports", there's nothing on your PC yet that ComposerFlex can send its notes to. Connect a MIDI interface or install a virtual MIDI port (below), then try again.

Sending the song to another program

To send the notes to another program on the same PC, such as REAPER or any other music program, you need a virtual MIDI port. It's a small program, installed separately, that passes MIDI from one program to another. ComposerFlex doesn't include one. Either of these two works with ComposerFlex on Windows 11:

• loopMIDI, by Tobias Erichsen, free to download: tobias-erichsen.de/software/loopmidi.html. loopMIDI makes no port by itself. Open it once after installing and click + to make one, called "loopMIDI Port". Its ports exist only while loopMIDI is running, so leave it running, and check that Autostart loopMIDI is ticked in the menu of its icon by the clock. Then the port is there each time Windows starts.
• LoopBe1, by Nerds.de: nerds.de/en/loopbe1.html. Once it's installed, its port, "LoopBe Internal MIDI", is always there, with nothing to set up. Its maker gives it free for personal use. For commercial work, you need to buy a license from their page after 30 days.

Neither one is made by Flex Music Labs. Download them only from their makers' pages above.

Once a virtual port is installed, it appears in the MIDI port list like any other port:

1. In ComposerFlex, choose it beside MIDI port.
2. In your music program, choose the same port as a MIDI input, on the track that should play the notes.
3. Click Start.

Playing from the Archive

Songs you play from the Archive tab go to the same place as Output.