Response headers for an mp3-file when using RewriteRule

Cache-Control:must-revalidate, post-check=0, pre-check=0, private
Connection:Keep-Alive
Content-Disposition:inline;
Content-Length:1413482
Content-Transfer-Encoding:binary
Content-Type:audio/mpeg
Date:Sun, 12 Feb 2012 15:25:41 GMT
Expires:0
Keep-Alive:timeout=15, max=99
Last-Modified:Sun, 12 Feb 2012 15:25:41 GMT
Pragma:public
Server:Apache/2.2.16 (Debian)
X-Powered-By:PHP/5.3.9-1~dotdeb.3