Soundproofing One Wall, Soundproofing Options

[sethjacquay]

I am going to be moving into a new apartment next month and
my new landlords warned me about a dude in the building next door
who might complain about sound.

I am interested in soundproofing the wall that the neighbor and I share
probably about 10' by 8' in size.

Obviously, headphones would work, but when I am singing and playing
acoustic guitar I will feel better about letting loose with some sort
of sound barrier on that wall.

Any suggestions?
Does anyone else have some sort of setup they use?

I was thinking about those foam absorbers, but I read that they actually
don't block the sound and might actually cause him to hear more noise.

I am considering a vinyl barrier that would hang from the wall. It won't block everything
but should add another layer to help reduce the sound transmission directly through the wall.