Most of the streaming music services offer free tiers -- including Spotify, Pandora, Amazon and YouTube -- but they do come with a couple of caveats. First, these are usually playlist services, in which you can pick a song and the rest of the tunes auto-generate -- you can't pick exactly what you want to play. The other potential downside is that they come with ads, and sometimes it's the same ad for every break.

At the time of writing, all of the services offer at least 100 million tracks each -- while Deezer says it has 120 million -- but that's not the end of the story. The number of songs offered by a music service used to be the main differentiator, but as always, it's quality over quantity that counts -- and particularly if you're looking for more obscure tracks. Depending on your favorite genre, some of the services may offer a better catalog for under-the-radar (Spotify), indie (Apple) or hip-hop artists (Tidal). Users who are less ambitious about expanding their musical taste should be satisfi

Without contracts, it's pretty easy to cancel one service and start with another. Swapping between music services isn't as straightforward as swapping between movie locker services using Movies Anywhere, for example. If you don't want to have to rebuild your playlists and library from scratch when you switch, you have two main options: a music locker service such as YouTube Music (but this implies you have a library of ripped or bought MP3s), or a library import tool such as Soundiiz. The latter is a service that lets you import the songs from each of your music services and transfer them, and