My PPA holds what I consider the most useful rhythmbox plugins available – at least for me … and looking at the stats – thousands of users out their similarly find them very useful.
This being Linux – there are many more opensource rhythmbox plugins & other stuff that interface with the player – all just waiting for you to experiment with.
For this article, I’ve had a trawl to find and link those plugins & scripts that more recent rhythmbox users can install. I cannot vouch for their usefulness, working state etc – but feel free to feedback your thoughts. If there is a ground swell of support (upvote, downvote on a comment) I will consider hosting an external plugin in my PPA.
The only reason why they have made them into this list is because the maintainers have updated them within the last 12 months – so – they are still loved … at least by their authors 🙂
If you know of something very useful that Rhythmbox users should be aware of – drop a comment. I’ll edit this article to keep it up-to-date.
Rhythmweb – an alternative rhythmweb to mine. This plugin was for a couple of years lost in the wilderness but the author has stepped in and is redeveloping it. This web-based interface hosts a REST interface and much more to control and query rhythmbox.
Hide-On-Close: For those users that are not Ubuntu distro users or are using a custom version of Rhythmbox that doesnt have the Ubuntu patchwork, this plugin mimics the Ubuntu capability – when clicking the X button, Rhythmbox hides, it doesnt exit and close.
Entropy: This is a plugin that stops Rhythmbox after playing the last entry in the play queue, instead of going back to whatever happened to be selected.
Beets Plugin:Beets Web plugin for Rhythmbox
Beets is the media library management system for obsessive-compulsive music geeks.
Google-Play: Plugin for playing music from Google Play Music in Rhythmbox. This currently doesnt work with RB3 but is useful of older RB users
Custom Playlists Format: This is a Rhythmbox plugin that allows the format of the playlist sidepane to be customized. For example, it can be used to show the genre instead of the artist.
Left-Feet: LeftFeet is a Rhythmbox plugin that generates a play queue from the library. It is designed specifically for a ballroom/Latin dancing society, but could be adapted to other purposes. Unlike a simple random generator, it tries to spread out genres that are in some way similar according to site-specific criteria.
Rhythmbox Alarm-Clock: A plugin to have an alarmclock in rhythmbox
Similar Tracks: Rhythmbox plugin to list similar tracks and similar artists in the right sidebar.
Rhythmbox Plugin Installer: A generic Rhythmbox plugin installer for users and developers.
Rhythmbox Remote: RhythmRemote is a Command Line remote to control Rhythm Box
LastFM Playcount: The Last.fm playcount synchronization plugin for Rhythmbox fetches the currently playing track’s playcount from Last.fm, and updates your Rhythmbox database accordingly.
Rhythmbox Apache: Rhythmbox plugin to stream music from Ampache
HexChat Plugin: /np plugin for hexchat and rhythmbox
Tweet By Rhythmbox: A simple script to send status of the current song to twitter
GoRhythmbox: An interface to the rhythmbox client with go[lang]
VIM Audiobox: Control Rhythmbox from VIM
DoubanFM: A plugin of rhythmbox that provides online music service of DoubanFM
Rhythmbox-Node: Another web front-end to Rhythmbox
Playlist-to-m3u: Converts playlists stored by Rhythmbox to M3U files
RhythmDB Mover: Move music files while updating the rhythmbox database simultaneously
Queue Album: Allows quick queueing of an album from within the library source view.
Rhythmbox CDDB: A plugin to do CD DataBase Search from rhythmbox
Rhythmsub: Rhythmbox plugin for streaming from Subsonic servers
LCDProc: This plugin enables the Rhythmbox music player to output information about the currently playing track to any display supported by the LCDproc driver. It allows Rhythmbox to be controlled by any keypad or infra-red remote control supported by LCDproc.
Cinnamon-Rhythmbox-Tray: Hide rhythmbox to systray when the quit button is clicked. Do not create systray icon, instead integrate nicely into cinnamon.
Playlist Randomizer: BASH script to randomize Rhythmbox playlists more effectively than the shuffle option provided by Rhythmbox.
OSD Lyrics: A simple plugin of rhythmbox that helps you to toggle lyrics display via toolbar button.
Rhythmbox Document Generator: HTML documentation generator for Rhythmbox
Rhythmbox-VK: rhythmbox-3 plugin for vk.com
Baidu Music: A rhythmbox plugin for playing music from Baidu Music.
Rhythmbox Pleer: A Rhythmbox plugin to listen music from Pleer
Ampache Plugin: This is a plugin for Rhythmbox music player that allows it to stream directly from an instance of an Ampache music streaming server.
YouTube Downloader: A rhythmbox plugin which downloads youtube videos by inputting username and password.
Digital Room Correction: Digital Room Correction plugin for rhythmbox
RB Merge Plays: Rhythmbox data merge from Last.fm
RBTidy: This plugin provides a toolbar which enables you to batch edit the title, artist, album and genre fields of your music files. Once the plugin is installed and enabled you will find the toolbar at the bottom of the song list. You will find 4 rows of buttons, switches, etc.
PlayInBackground: For non-ubuntu users (this is the default in Ubuntu) – this plugin allows you to play music when “closing” rhythmbox i.e. rhythmbox hides instead of closes.
The following plugins look like they just need a little bit of love and attention to make them work. Fork and fix!
Rhythmbox-Spotify: Out-of-tree spotify plugin for Rhythmbox
Playlist Identifier: Adds an item to the playlist track contextual menu which shows which playlists each track is part of.
Rhythmbox-Echonest: A rhythmbox recommendation plugin using data from the Echo’s Nest.
Rhythmbox Record Radio Station: Rhythmbox plugin to record internet radio stations
Playlast.fm: PlayLast.fm is a rhythmbox plugin to create playlist from Last.fm scrobbles.
Now Playing Text: Rhythmbox plugin that prints artist, song, and rating to a text file.
vkontakte: rhythmbox-vkontakte is a rhythmbox plugin for searching and listening to vkontakte (vk.com) audio records
LastFM Extension: Love/Ban buttons, playcount synchronisation, and fingerprinting your songs so that you can find out the real details of an unknown or mis-tagged track
Rhythmbox Seek: A simple plugin for Rhythmbox to seek forwards/backwards in the current track.
Send First: This Rhythmbox’s plugin allows you to put a song in the beginning of the play queue
WebMenu: find and display information about your music from lots of online sources.
Stop After Current Track: Add the ability to stop playback immediately after the current song has finished playing
Rhythm-Remote: Stylish mobile web browser interface to rhythmbox
EDITED 03 June 2014: Added additional plugin that need a bit more love and attention
xpress-ubuntu 
unfortunately THEY changed things in the new v3 RhythmBox
the old plug-ins no longer work