Spoke tension for 36" wheel?

Hi there,

I found some comments about the “right” spoke tension to be “between 20 and 24” of whatever when measured with the “cheap” ParkTool.
I don’t want to buy such a tool and i don’t know what exactly it is showing, but i also found a site about checking spoke tension by ear but there table only goes up to 308mm spoke length.
So i am asking how do you check spoke tension on your 36"er and too what level do you adjust it.
Or if you think your spoke tension is right and what should be recommended can you tell us what note you hear when plucking a spoke? (i was using a clip-on guitar tuner, using a crank arm to clip-on the sensor and right now all my spokes are around E 4)