In attempting to play an iHeart radio station with Rhythmbox under Ubuntu 16.04 I get two error messages. Rhythmbox is working correctly with the default sample radio stations.
The first error message: "Your Gstreamer is missing a plug-in".
The other error message: "Rhythmbox requires to install plugins to play media files of the following type: application/x-gzip decoder."
How can the missing requirements be installed to enable Rhythmbox to play an iHeart radio station?