I first picked out the music I wanted (taken from the Youtube audio library) and imported it into Houdini, setting up a geometry, chopnet, box, and transform to begin with. I wasn't really sure what I was going to do for this animation, what I wanted it to look like, or where to start with it, so I just played around with the different things I could do using procedural animation which allowed me to get more comfortable with it as a whole and figure out what I liked and what direction I wanted to go in. I ended up aiming for a more abstract animation. 

I set up a spent some time messing around with the chopnet, adjusting the waves and such so that the box moved how I wanted with the music. 

After adding and changing things (foreach, transform and retime nodes), I experimented with the bend and mirror nodes to create a circle shape, adjusting everything until I was happy with it. 

Added a simple ocean wave for the floor to create interest, as well as a tunnel of cubes using the same ocean nodes, copy to points, and a bend node. I also added some keyframes for the scale of the cubes to give the illusion of the tunnel opening up and fading away at the end. I liked the idea of the camera beginning in the tunnel and moving through it until it comes apart at the end.

I later added a ring of spheres animated using ocean nodes and a second procedural music ring, and added keyframes to both so that they would rotate around the sphere in the center. I set up the first bit of camera animation, and took the first procedural animation and adjusted it, adding a twist node, to create some spires. I had the idea for the spires to slowly ascend from the floor as the camera moved forward, trying to match the somewhat ominous vibe of the music with the creeping movements as well as the colours I add later. 

After my basic camera animation had been set up, I just created and added materials to the different objects, and adjusted the lighting to make the scene feel more dramatic to match the music. I spent some time rendering one frame at a time in MPlay adjusting details, final camera angles and animation so that it came out well in the final render.