Rhythmbox is the Gnome's default music player.
Read this explanation from the Official Ubuntu Documentation.
Version 3.4.3 has been released with numerous bug fixes.
Not least of which includes:
Improved Android plugin to work better with Samsung and Android 9 devices
Replaced status bar with floating bar as used by Nautilus
Fixed crash when store request processing fails
Fixed crashes when editing auto playlist sorted by Location / Bitrate
Fixed crashes when insert a cd
Fixed issue that can not transfer songs to phone over MTP
In order to install the latest PPA and benefit from the new version, open a terminal and run the following command:
sudo add-apt-repository ppa:ubuntuhandbook1/apps
Then launch Software Updater to upgrade the music player packages
You can purge the PPA which will also downgrade Rhythmbox to the stock version (3.4.2-4ubuntu1) via the command in terminal:
sudo apt install ppa-purge && sudo ppa-purge ppa:ubuntuhandbook1/apps