I finally figured out what’s wrong with my setup: I need to use the copy of python that comes with Paraview, which is a 64-bit version, and not the copy that came with MacOSX, which is a 32-bit version. I kept running out of memory not because the arrays were so huge, but simply because 32-bit python can’t handle these arrays. So I have converted everything to .npy files and I’m now ready to start try synthesizing some sounds!