Click "Choose Songs" and select mp3 files from your hard drive (use cmd-click or shift-click to select multiple songs.) Then click "Analyze." The songs will upload to our analysis servers. After each song has been uploaded, you will receive a code. Click on the code to launch a new browser window with the xml file in it. You may need to wait a few seconds for a free processor to get to your file; if you get this message simply reload the browser window. The XML file will be zipped, on some browsers it might just appear on your Desktop.
Temporary instructions:
Download this script and rename it to enAnalyze.sh, giving it executable permissions (chmod +x enAnalyze.sh.) Then simply run ./enAnalyze.sh path_to_mp3_file.mp3, and wait for it to upload. You'll receive a 32-character code for the song: visit http://analyze.echonest.com/xml/code, replacing the word "code" with the actual code, in a minute or so to see the analysis.