Apple just a few weeks ago released iTunes Match, which stores your music on the cloud and streams it to your gadgets. Google started selling digital music in November and also offers cloud storage. Amazon pioneered the option of cloud-based delivery and storage back in March.
These three heavyweights are all competing for the estimated $7 billion per year spent on online music. All three services are good, but each has quirks, too.
Deciding which to use starts - at least for now - with your choice of media player and your listening preferences. While iTunes Match is probably slightly better in the balance, that isn't going to matter if your smartphone or tablet is an Android, for instance.