This is an application, called Hyena, for hearing how cancer (and cancer therapy) works. While there is an overwhelming complexity in the science and medicine of cancer, the essence of the disease can be heard and understood when it is translated into music. Here you can upload any piece of music in musicXML format. We will simulate the evolution of cancer (and the effects of therapy if you want), and give you back an mp3 sound file, a midi file and/or a pdf of the sheet music.
Our software simulates an analogy between the cell types in a body and the parts of a piece of music. Like musicians in a symphony, working together to produce a piece of music, different cells in our body work together to produce a living, breathing person. In this analogy, cancer starts with a musician ceasing to play her assigned part, and starting to repeat her last few measures, replicating that motif, generating another part, with some probability, every time she repeats. We call that probability of generating a new part, the reproductive rate of that part. Cancer cells stop doing the work of their organ, and start replicating out of control. As they reproduce, they also mutate, and sometimes a mutation gives that cancer cell an additional advantage, replicating faster or surviving better than the other cells. It is a microcosm of natural selection at the cell level. In music, we can hear this as mutations and variations in the cancer motif, and in the rate at which the cancer motif replicates itself. A growing, dissonant, monotonous and yet relentless cacophony slowly take over the symphony.
Even the genetic details of the kinds of mutations that occur in cancer can be translated into music. Single nucleotide mutations (single letters of the DNA) have a natural analogy in single note changes. Small insertions or deletions in the DNA can be represented by small repetitions and deletions in the motif. Sequences of letters can be reversed in DNA, just as portions of the motif could be reversed, and so on. Cancers often fuse part of one chromosome to part of another chromosome (called a “translocation”). We can model this by taking a part of the cancer motif and fusing it to a randomly selected part of some other motif in the original piece. We also allow mutations that transpose the cancer motif up or down by one half-step. Each mutation adds dissonance as different cancer parts randomly diverge. If a mutation changes the reproduction rate of the part, we note this by selecting a new timber for the part with the new rate.
Cancer therapy can also be represented in music. Most therapies are able to kill the vast majority of cancer cells, but it is often the case that some mutant cells, by bad luck, have a mutation that makes them resistant to the therapy. They survive and replicate, eventually regrowing a tumor that is entirely composed of resistant cells. This could be heard in music, as most of the cancerous, repeating parts are silenced, but some parts, resistant to the therapy, are left behind to replicate again. Because there is often a tradeoff between reproduction and survival, we set the chance that a part is killed by therapy to be equal to its reproduction rate (signified by the timbers).