If you are looking for a great way to stream music on your Roku for free, Pandora may be the channel app for you.
I have been using the free Pandora channel app on my Roku for about 2 years now and love it.
With the free Pandora music streaming app, you can create channels based of of your musical artist interests, and Pandora will serve up related songs in that genre.
There are occasional ads, and limited song skips in the free version of Pandora.
More info from the developer:
Listen to your Pandora stations or create new ones based on a song or artist. Pandora’s world of analyzed music, almost a century of popular recordings – new and old, well known and obscure – lets you enjoy old favorites and discover new ones. Optional upgrade to Pandora One available.