A couple songs I tend to play when I am in a melancholy or contemplative mood. Not necessarily slow, but not the tempo I usually prefer by default. I'm sure I've mentioned at least 2 of these before, so they may not be new to you, but you shared a Metallica song, so I won't feel bad if these less-known songs are repetitive.
Something, Somewhere by Phil Keaggy, Wes King, and Scott Dente
Goodbye, Goodnight by Jars of Clay
Weighty Ghost by Wintersleep
(breaking the unintended word, word title trend)
Hopefully the links aren't blocked in Australia, or you can find the songs by title and artists if they are.
I really like Jars of Clay, something about their music appeals greatly although it's a mood thing, I guess not unlike most music.