This dialog lets you play back previously recorded performances. To display the dialog, use View/Record Player. If you've just completed a recording, the dialog opens it automatically. Otherwise you must select a recording, via the dialog's Open button. To listen to the recording, press the Play button. Press it again to pause playback. To stop playback and rewind to the beginning, press the Stop button. To skip around within the recording, use the position slider.
The dialog opens .cemr files, which the record function creates in addition to standard MIDI files. The .cemr file includes the port and channel associations, i.e. for each part, which port and channel it was output to. This is in contrast to standard MIDI files, which are incapable of storing port associations. If the recording was made with a MIDI setup involving multiple output devices, playing the resulting MIDI file can give unexpected results: parts that were originally on different devices may share the same timbre, and may no longer be distinguishable. The .cemr file avoids this problem. When a .cemr file is played back, assuming the output MIDI setup is identical to what it was when the recording was made, the performance should sound exactly as it originally did.
This dialog also lets you modify the port and channel associations of an existing recording. This facilitates playing back a recording through a different MIDI setup. It's recommended to stop playback first, otherwise stuck notes may occur. To change a port or channel, left-click the port or channel within the list control, and type a new value in the popup edit box. The part names can similarly be edited, and individual parts can be enabled or disabled using the checkboxes. After changing the part information, you can save the edited recording via the Save As button. You can also export the recording as a new standard MIDI file, via the Export button. The export feature allows you to create a MIDI file with a different resolution than the original MIDI file had.