Answer:
A dagger thrust at my own heart, dictates the way I'm swayed. Left I stand, and right I yield, to the twisting of the blade.
What can be measured but not seen?
The land was white the seed was black it'll take a good scholar to riddle me that. What is it?
My first master has four legs, my second master has two. My first I serve in life, my second I serve in death. Tough I am, yet soft beside. Against ladies cheeks I often reside.
What stays the same size no matter how much they weight?
I can only be played on a windy day