I want one song to repeat. Unfortunately, this is not possible. The only possible solution is to create a playlist with that one song and play it on loop, but this is not convenient. Are there any plugins or tweaks to get this functionality?
Repeat once functionality is inbuilt to this plugin via the play-toolbar popup
As the author I've described this in my blog. In summary, install via my PPA package (PPA instructions below) "rhythmbox-plugin-alternative-toolbar", or following the manual installation instructions at the project homepage.
There is now a useful plugin you can add to Rhythmbox to give you this functionality.
"Repeat one song" feature for Rhythmbox
Adds a toolbar option to repeat the selected track when the toolbar option is clicked.
Note - it does not repeat a song from the Play Queue.
to install
You can use the instructions in the link below to add my PPA and install the plugin ("rhythmbox-plugin-repeat-one-song").
Alternatively,
download the .tar.gz file from the homepage (link above), extract and copy the files into the folder ~/.local/share/rhythmbox/plugins/repeat-one-song
Start Rhythmbox, enable the Repeat One Song plugin: Edit --> Plugins
For v2.99 and later the "Repeat one" button is replaced by the source "Edit - Repeat Current Song" menu option
Linked Question:
