Group data by child node

I'm not sure if what I want to do is possible so first ill just explain it. 
I have a xml playlist such as http://sysrq.tk/temp/playlist.xml and using 
XSLT I would like to convert it to look like 
http://floam.sh.nu/files/playlist.html however I do not know how to group 
the songs by albums, I tried matching album = album[position()-1] but I 
could not use an if around the <h2> and the <ol> because the closing of the 
if did not include the </ol>. If anyone could tell me if this is at all 
possible using XSLT I would be most greatfull after trying myself and 
looking around for similar examples and have come up fruitless.