These are the controls with with which you record and play midi music.  Each of these buttons can appear in different colors -- red or green --, and showing a different state -- raised or depressed -- depending on your actions, such as whether you have selected the midi IN and/or the midi OUT device, whether you have turned the devices ON, and whether you want to record or play midi.

This table shows how the buttons are drawn depending on your actions:

Neither the midi IN not the midi OUT devices have been selected.  All buttons are shown in a disabled state.

midi IN selected but not started. Click on the green dot to start the device and begin receiving midi messages. Midi OUT device not selected.

midi IN selected and started.  Midi messages are being received and reflected on the keyboard.  Click on the red dot to begin recording. Midi OUT device not selected.

midi IN selected and started.  Midi messages being recorded.  Click on the record button or on the stop button to stop recording.   Midi OUT device not selected.

midi OUT selected but not started. Click on the play button again to start the device.  No midi messages will be sent until started. Midi IN device not selected.

midi OUT selected and started.  All sound produced by FastChords is played on the midi instrument.   Midi IN device not selected.

midi OUT selected and started.  The program plays previously recorded midi to the midi instrument. Midi IN device not selected.

Both midi IN and midi OUT devices selected but not started.  Until the devices are started, no midi messages will be received from or sent to the instrument.

The midi IN and midi OUT devices cannot be in a started state at the same time.  When both devices have been selected (with the menu, see Selecting the Midi IN Device and Selecting the Midi IN Device) starting one stops the other.  This is automatic.  In other words, you cannot play and record midi at the same time.

Here both devices have been selected and the midi IN device has been started.  Midi messages are being received.  The midi OUT device is stopped.

Here both devices have been selected and the midi OUT device has been started.  FastChords produced sounds send midi messages to the midi instrument.  The midi IN device is stopped.

This cannot happen.  Both midi IN and midi OUT devices are shown started at the same time.

Remember: selecting the devices is not enough to receive or send midi messages.  The devices must also be started.