When Amazon announced its new streaming music service, it butted its way in to a room already crowded with players. Some, like Pandora, focus on custom radio-like experience, while others, such as Beats and Spotify, offer vast catalogs of music on-demand for a flat monthly fee. Apple and Google (and now, too, Amazon) stream music in various ways, in order to appeal to widely differing preferences of their users.

Here's a quick guide to all the streaming music options that matter:

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