youll need to tune your A string down so that its 7th fret matches your open G string. 
is the tuning mark used on his 2 string slide bass.


---------------------------------------------------| (every other time
-0--03b-00-2-2-5-2-3-3-6-6-6-6-6-6\----------------|  it slides up to the
---------------------------------------------------|   9th fret instead of
---------------------------------------------------|  sliding out)
dont worry im not lookin at you....

-------------------------------|
-0~~~~~~~~~~~~-----------------|
-7~~~~~~~~~~~~-----------------|
-------------------------------|
whisper me your number, ill call you up at home