Add value to rotation each frame.

Hello I am new here I have a question that ive been trying to answer forever. I cannot for the life of me figure out how to do this.

I am inside of the curve editor using a script controller.

I need to add the value of the z rotation from the last frame to the value of the z rotation on the current frame....

I am using audio float which I can use pretty well, but with scripting it doesn't seem to want to allow me to convert its value to a useable number ever. everytime I try to do math to the value it throws one of many errors. Like unable to convert OK to type float.

Or unable to convert "float number" to undefined. etc

I would like to have the audio float value add to the value of what it is controlling not just add the value and then when the volume goes down it undoes what value it has added.

I add a cube and setup the z rotation to an audio float controller select my audio track and it works perfectly

audio volume goes up cube rotates, but as soon as the audio volume goes down the cube "unrotates" to its original position.

I would like to essentially always add the value of the audio float to the rotation value of the cube and never let it return, always rotating foreward.

PLEASE help me this is driving me absolutely INSANE

here is a screenshot of what I have so far..

Thank you in advance