Sometimes you will want to save a snapshot of the current state of a session for possible use in the future. For example, you may be about to change the entire arrangement of a piece, or drastically alter the signal processing, and want a reference to come back to, should that not work out.

This is easily accomplished using Session > Snapshot. A small dialog will appear, allowing you to enter a name for the snapshot. The default name is based on the current date and time.
You can create any number of snapshots.

Creating a snapshot does not modify your session, nor does it save your session. Instead, it saves an alternate version of the session, within the session folder. The snapshot shares all data present in the session.

After creating a snapshot, you can continue working on the session and save it normally using Session > Save and any existing snapshots will remain unchanged.

Switching to a Snapshot

If you are already working on a session and want to to switch to an existing snapshot, navigate the Snapshot List. Find the name of the snapshot in the list and click it. Ardour will switch to the snapshot. If there are unsaved changes in the current session, Ardour will ask what you want to do.

Starting Ardour With a Snapshot

Since a snapshot is just another session file stored within the session folder, you can specify that "version" when loading an existing session. The browser in the "Open Session" dialog will show an expander arrow for sessions that have more than 1 session file (i.e. snapshots) present—click on it to see the list, and then click on the name of the snapshot you want to load.

Saving and Switching to a Snapshot

Sometimes you may want to create a snapshot and then have all future edits and modifications saved to that snapshot rather than the main session. This is easily done using Session > Save As. This does not create a new session folder, but saves your session as a new snapshot and then switches the "current snapshot" to the newly created one. All subsequent saves of the session will be stored in this new snapshot, and existing snapshots (and the main session) will be left unaffected.