There are instructions available across the Internet about how to re-tune music to A4=432Hz with the audio player foobar2000 and plugin SoundTouch. This is very nice but since this involves real time pitch shifting of the music it creates unwanted artifacts in the sound. Instead of changing the pitch it is also possible to change the rate of playback. This will slow the music down a bit (1,82%) but in my personal opinion this sounds much better, with no audible artifacts. This is how you do it:
1. Download foobar2000 and install it if you don’t already have it, it’s free.
2. Download the SoundTouch plugin, unzip the archive and copy the containing file ‘foo_dsp_soundtouch.dll’ to the components folder of the foobar2000 installation folder.
3. Run foobar2000 and go to File > Preferences. Once in there go to Playback > DSP Manager. In the rightmost list with available DSPs you should see ‘SoundTouch’. Double-click it to add it to the list of active DSPs. In that list you should select ‘SoundTouch’ by clicking it once and the click ‘Configure selected’.
4. Copy the configuration from the image below (check rate adjust and set it to -1.82%, fine tune with arrows on keyboard). Click OK and then OK again in the Preferences window and that’s it!
If you need more thorough instructions on how to install foobar and the SoundTouch plugin, go to this page: http://www.anotherwindowsblog.com/2010/04/how-to-easily-adjust-song-pitchspeed-foobar.html
Side note: remember that not all music is tuned to the disharmonious reference frequency of A4=440Hz, Jimi Hendrix used to tune to somewhere around A4=432Hz, maybe a bit lower (he tuned to what he thought sounded best). Also while checking some YouTube videos me and my friends noticed that Bob Dylan tuned at least some songs to pure A4=432Hz.