With Session Management you can easily restore complex sessions involving numerous applications including their particular state. Hydrogen does support some Session Management systems too.
All the supported Session Management protocols are Linux only. There is no (tested) support for MacOS and Windows yet.
NSM: Non Session Manager (NSM) is of 2021 the de facto standard in Session Management tools within the Linux audio community and Hydrogen does over full support and compliance to its API.
We highly recommend using this protocol for Session Management.
LASH: Hydrogen provides a basic support for LASH Audio Session Handler (LASH). This covers recalling the song used within the session but, unlike the NSM support, no recalling of the JACK connections and no per-session preferences.
You have to activate LASH support in the General tab of the Preference dialog in order to use it.
Hydrogen will be under session management if you start it via a NSM server application, like RaySession. You can easily check whether Hydrogen is aware of the session by checking out the
Project option of the Main Menu as some action will have changed in order to comply to the NSM API.
Replace With New Song instead of New. Replaces the song associated with the session by an empty one.
Import Into Session instead of Open. Replaces the song associated with the session by a song of your choice.
Import Recent Info Session instead of Open Recent. Replaces the song associated with the session by one of the recently used songs.
In contrast to the Save As command the underlying path of the current song will not be changed. All subsequent Save actions will store the current state of the song to the file in the session folder and not to the path of the exported file.
Both the song and the preferences associated with the session will be stored in a session folder called
Hydrogen.*. In addition, the drumkit (and its samples) used with the song will linked into the session folder as well. If the link is replaced by a folder containing a valid drumkit, this one will be used over the system and user drumkits.
This allows you to create fully self sufficient backups of your Hydrogen session using tar -chf. These can even be ported and used on systems which do not have the required drumkits installed.
Note that only the stock drumkit loaded last will be linked in the session folder. In case you only alter instrument parameters or delete instruments or samples this will work perfectly fine. But as soon as you add instruments from other drumkits or external samples, the linked drumkit folder won't contain all samples required by your current song anymore. You need to saved the kit (or create a new one) in order to ensure consistency.