Other plugins can play videos and make you tea. PlayPress has a laser focus on just one thing: it lets you put an audio player in blog posts and pages.
You use a standard WordPress shortcode like this:
[audio mp3="http://example.com/bells.mp3" ogg="http://example.com/bells.ogg"]
Users of most modern browsers will see a native HTML5 audio player. In older browsers, an adequate Flash-based one will be shown.
You don't even need an Ogg Vorbis file:
In this case, PlayPress will first attempt to show the Flash player. If Flash isn't installed, readers will see the HTML5 audio player – but it won't work in Firefox or Opera. (Most Firefox and Opera users should have Flash installed.)
In either case, if neither Flash nor HTML5 are supported by the browser, users will see a link to download the audio file. Graceful degradation.
Optionally, specify a title and/or artist for display in the Flash player (this will override the ID3 metadata embedded in your MP3 file, which is otherwise used if present):
[audio mp3="http://example.com/bells.mp3" title="Imagine" artist="John Lennon"]
The author's website has PlayPress running live right there on it.