RMT can be used to produce 2 (16bit) or 4 (8bit) channels of music for the POKEY chip.
The Instrument slot is selected by clicking 00: Instrument 00. Instrument definitions can be loaded into these slot using the menu Instrument > Load and Paste to Actual Instrument. (note it is possible to use instruments from other tracks by saving/loading to instrument files).
Notes are entered by typing on the keyboard; the allowed range spans 6 octaves, which are selected by clicking Octave 1-2.
Tracks are numbered, and can therefore be re-used inside the song definition list on the right side of the screen.
To finalize the song, click below the last line of your song definition list, and press the key “G” to insert Go to line 00. The song can now be saved with File > Export As… Make sure the export options match those shown below, including the address (HEX) C000.
(NOTE: In case you would like to use “ready-made” RMTs in your project, make sure to relocate them to address $C000 by loading and re-exporting through the RMT software)