The 'Custom music cues' option allows you to input any music cue that's not on the HedgeModManager list.
This can be used to play songs from the Jukebox (vanilla or modded), any Guardian theme, ending song etc.
However, music from some archives may have playback issues, those being: any Boss theme, any Update 3 exclusive music ('Second Wind' uses a workaround) or the Birthday mix.

HOW TO ADD CUSTOM MUSIC CUES:

- Enable the 'Use a custom music cue?' option in HedgeModManager

- Open 'config.ini' using a text editor

- Under 'Music_Custom', input a new music cue (text that starts with bgm_, for example: bgm_custom01, end result should look like this: PhaseCue="bgm_custom01") and save the file.

- Done!


HOW TO GET MUSIC CUE NAMES:

The easiest way to find a song's music cue is to open one of the music archives (for example: '<game folder>/image/x64/raw/sound/custom_sound/bgm_custom.awb') in foobar2000 with the vgmstream plug-in installed. 

After finding your music cue of choice, follow the instructions above to add it to 'Music_Custom'.