In addition to the instructions in this topic which really helped me, here is a little magic to use the native Linux apps from MusicBee (like sending files to Picard without installing the Windows version in Wine). I'm using this with Picard, Spek and VLC (all installed with flatpak, but this can work for any native application. Probably).
How to connect MusicBee to Linux native applicationsOn your Linux host, create a file named `send_to_linux.exe` and paste this:
#!/bin/sh
$1 "`wine winepath -u "$2"`"
Put this file in `$HOME/.wine/drive_c`. If you are using a wineprefix, adapt to `/path/to/your/wineprefix/drive_c`.
Now open MusicBee, go to Settings > Tools and add an external application:
- name: The name of your application
- application path: C:\send_to_linux.exe
- parameters: here is where you'll adapt the command to each application:
# Native Ubuntu explorer
"nautilus" "<URLs>"
# MusicBrainz Picard
"flatpak run org.musicbrainz.Picard" "<URL>"
# Spek
"flatpak run cc.spek.Spek" "<URLs>"
# VLC
"flatpak run org.videolan.VLC" "<URL>"
Some apps are using
'URL' and other are using
'URLs'. This is because 'URL' will send all the files to the application. That's a good thing for Picard or VLC, but not for Spek or the file explorer, which will open as many windows. For those applications, using 'URLs' allows to only send the first selected file.

Save and close settings. Now you can right-click files and "Send to > External tools > Picard".
Extra config for VLCMake sure those settings are enabled in VLC (Tools > Preferences > Interface tab):
- Allow one instance only
- One instance when started from file
- Queue items to playlist when in one instance mode
Flatpak and folder access(happened to me with Spek and Picard)
If you're using flatpak applications, there a possibility they won't be able to access the folders where you keep your music, or the music path inside your wineprefix.
In my case, there were two locations I needed to whitelist:
- the actual location of my music library on my linux host (could be something like `/media/path/to/my/music`')
- the path provided by wine: the winepath command used in the script is outputting a path like `/home/username/.wine/dosdevices/c\\:/media/path/to/my/music`, which is symlinked to the actual folder for my music library.
You can generally confirm if the problem comes from storage permissions by attempting to open those two folders in your application. In my case, Spek didn't see the `.wine` folder, nor my library folder, so I had to whitelist the two locations :
sudo flatpak override cc.spek.Spek --filesystem=/home/username/.wine/dosdevices
sudo flatpak override cc.spek.Spek --filesystem=/media/path/to/my/music/
WARNING: This means Spek (or whatever app you're using) can access all the files contained in `/home/username/.wine/`. You can be more strict and only allow access to your library by giving access to specific folders, but I have libraries in several locations and didn't care enough.