somafm, Use Apple Music.app on your Mac?
Here's an easy way to add all the SomaFM channels at once:
Go into Music.app, and Cmd-U (File -> Open Stream URL) and paste in:
This will add all the SomaFM channels to a playlist called "SomaFM". (It also seems to put them in another playlist called "Internet Songs" but you can delete them from there with no problem.)