No, e.g. I use this rule in my .htaccess on my blog:

  RewriteEngine On
  RewriteCond %{REQUEST_URI} !^.*\.html$
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteRule ^(.*)$ %{REQUEST_FILENAME}.html

Which means you can access:

http://tycho.ws/music or http://tycho.ws/music.html