(First off: this is my first tab. I'm a bassist and a Portal 2 fan [and especially a fan
of the music]. Secondly: yes, I realize that I am bass-tabbing a techno song from a
video game OST. Hopefully I've come close to recreating the sound. If not, tab it with a 
different instrument and see how it comes out. Otherwise, enjoy!)

This song is pretty simple in that there are essentially two main bass parts. I've cut
them up for readability, but here they are.

PART 1
G|---------|----------------------------|
D|---------|-----10------8--------------|
A|----5-6--|--8------11-----10--11--8--7|
E|---------|----------------------------|

G|----------------------------|
D|-----10------8--11------8---|
A|--8------11---------10-----7|
E|----------------------------|

PART 2

G|-----------------------|
D|----10---------10------|
A|--8----10-11-8----10-11|
E|-----------------------|

G|---------------------|
D|----10----8-11----8--|
A|--8----11------10---7|
E|---------------------|

Essentially, the only difference is the speed at which you play. You can do a lot with
this bassline, improvising as you will or sticking with the original song formula. I've
had a lot of fun trying to learn this and, as I said up at the top, this is my first tab 
- therefore any tips and advice are welcome!