To setup global hot keys:

Open Preferences and select the Hot Keys section.

Record the desired key combination for each action.
To control Beatler in the background you can assign global hot keys to the following actions:
Start/Stop the player.
Play the next track.
Play the previous track.
Play the next release.
Scan forward in current playing track.
Scan backward in current playing track.
Add the current playing track to the default crate.
Hide/Unhide Beatler
Open Preferences and select the Hot Keys section.
Record the desired key combination for each action.