In that code replace
PHP Code:
if ( is_single() OR is_page() ) {
with
PHP Code:
if ( (is_single() OR is_page()) AND !is_page('About') AND !is_page('Privacy Policy') ) {
Or to exclude many pages
PHP Code:
if ( (is_single() OR is_page()) AND
!is_page(array('About', 'Privacy Policy', '25', '119', 'some-page', 'another-page')) ) {
In the last example I mixed page titles, page ID's and page names (= the URL part of a page when using Permalinks, i.e. mysite.com/blog/
some-page/). All three methods of page identification (ID, title, name) can be used, and they can be mixed.