Question Realtime Music Visualizer

I'm new to shaders and I'm just sorting out the differences between unlit shaders, shader graph, and compute shader, etc. etc...

What I'm interested in demoing is a simple spectrum visualizer. I want to map the amplitude over a 2D texture and do it realtime. Here's pseudo code for what I want to accomplish:

// CPU

Update:

   float[256] spectrumData = AudioListener.GetSpectrumData()

   SetShaderBuffer(spectrumData) // normalize to 0..1 values?

   RenderTexture()





// GPU

Shader:

  Vertex:

     color = white if texcoord.y < spectrum[texcoord.x] else black

     return color

Help me fill in the blanks of using the right shader solution for this, and the right datatype (texture? crt? buffer?) to pass spectrum data along to the gpu.