CS Cart MP3 player in shop. For this you need the following.

description.tpl

/* Xander Smalbil */
// description.tpl

{* $Id: description.tpl 11191 2010-11-11 11:56:01Z klerik $ *}
{** block-description:description **}

{if $attachments_data}
  <div id="mp3_attachments">
    {foreach from=$attachments_data item="file"}
		{if $file.filename|strstr:'.mp3'}
		{literal}
			<script type="text/javascript" src="http://wpaudioplayer.com/wp-content/plugins/audio-player/assets/audio-player.js?ver=2.0.4.1"></script> 
			<script type="text/javascript">
			<!--
				AudioPlayer.setup("http://wpaudioplayer.com/wp-content/plugins/audio-player/assets/player.swf?ver=2.0.4.1", {width:"290"});
			//-->
			</script>
		{/literal}	
			
		{assign var=mp3location value="`$config.http_location`/var/attachments/product/`$_REQUEST.product_id`/`$file.filename`"}
			
		<p id="audioplayer_{$file.attachment_id}">Mp3 sample is unable to load</p>
		{literal}
			<script type="text/javascript">  
			<!--
				AudioPlayer.embed("{/literal}audioplayer_{$file.attachment_id}{literal}", {soundFile: "{/literal}{$mp3location}{literal}"});
			//-->
			</script>
		{/literal}
		{/if}
		{/foreach}
	</div>
{/if}

{$product.full_description|default:$product.short_description|unescape}

htacces

/* Xander Smalbil */

// var/.htacces

Order deny,allow
Deny from all
<Files ~ "\.js$">
  order allow,deny
  allow from all
</Files>
<Files ~ "\.mp3$">
  order allow,deny
  allow from all
</Files>