Also check out http://freestyler.ws/style/70883/google-music-player-hide-auto-playlists and http://freestyler.ws/style/79105/google-music-player-cleaner-playlists if you want a more compact navigation column on the left.

UPDATE 05/06/2015 - Header clean up

UPDATE 04/17/2015 - Clean up Listen Now section and move Genre picker higher.

UPDATE 04/14/2015 - Clean up header, make tweaks to Listen Now headers, and include "Refresh station" button in Queue.

UPDATE 03/17/2015 - Clean up header

UPDATE 01/16/2015 - Clean up header

UPDATE 01/05/2015 - Clean up header

UPDATE 11/25/2014 - Clean up "Playing From" section

UPDATE 11/7/2014 - Add "Save Queue" and "Clear Queue" buttons to Queue header

UPDATE 8/4/2014 - Remove Google+ Share button in header

UPDATE 7/16/2014 - Cleanup Header. Queue "Playing From" header no longer appears to be displayed but keeping the updates from 5/14/2014 just in case it returns.

UPDATE 6/6/2014 - Cleanup Header

UPDATE 5/14/2014 - Update Queue to make the "Playing From" header shorter and display band information across the album art

UPDATE 4/17/2014 - Cleanup header

UPDATE 3/7/2014 - Cleanup header

UPDATE 1/27/2014 - More cleanup

UPDATE 12/4/2013 - Additional header section cleanup

UPDATE 11/4/2013 - More tweaks to keep the header section clean.

UPDATE 10/25/2013 - Update UI after more changes to header section.

UPDATE 10/3/2013 - Update UI after major changes to header section.

UPDATE 7/31/2013 - Tweak UI after slight changes in header section by Google.

UPDATE 6/24/2013 - Changes to the header color scheme and made the search field rounded. Tweaked the navigation sidebar. Reduced the size of the shortcuts menu (accessible using 'Shift+?') to make it readable.

UPDATE 5/17/2013 - Update for the complete redesign of Google Music. There are probably some adjustments that can be done to reduce the width of player bar.

UPDATE 5/7/2013 - Update for changes to Google Music site formatting, tweaked the interface with the largest change being the search field now only displays when you hover over it with a mouse.

UPDATE 3/4/2013 - Hopefully clears up the Navigation column margin issues.

UPDATE 2/27/2013 - Quick update for changes to Google Music site formatting

UPDATE 10/5/2012 - Additional tweaks for when Google Play popups for available music. If you use this userstyle, I'm looking for feedback on whether you want these popups to be displayed at all.