In his book Gödel, Escher, Bach, Douglas Hofstadter makes an explicit analogy between genes and music:
Imagine the mRNA to be like a long piece of magnetic recording tape, and the ribosome to be like a tape recorder. As the tape passes through the playing head of the recorder, it is “read” and converted into music, or other sounds…When a “tape” of mRNA passes through the “playing head” of a ribosome, the “notes” produced are amino acids and the pieces of music they make up are proteins.
Music is not a mere linear sequence of notes. Our minds perceive pieces of music on a level far higher than that. We chunk notes into phrases, phrases into melodies, melodies into movements, and movements into full pieces. similarly proteins only make sense when they act as chunked units. Although a primary structure carries all the information for the tertiary structure to be created, it still “feels” like less, for its potential is only realized when the tertiary structure is actually physically created.
Now, using a program called Gene2Music, you can transcribe any DNA sequence into music. The program, which was developed by molecular geneticists Rie Takahashi and Jeffrey Miller of the University of California, Los Angeles, uses an algorithm that converts each codon in the DNA sequence into a musical chord. Codons for hydrophilic amino acids (which are attracted to water) have a high key, codons for hydrophobic amino acids (which are repelled by water) have a lower key, and the duration of each chord is determined by the frequency of its corresponding codon within the transcribed DNA sequence.
Using Gene2Music, Takahashi and Miller have so far generated more than a dozen pieces of music, including transcripts of the huntingtin and cytochrome c genes. The aim of the project is to make the visualization of proteins easier for scientists, and to make molecular biology more comprehensible to non-scientists. Takahashi says it was inspired by a blind meteorology student and Cornell University, who devised a method by which the different colours on a weather map could be converted into musical tones.
This isn’t the first time DNA sequences have been translated into music. In 1995, for example, the British band The Shamen collaborated with Ross King to produce a track called S2 Translation, which is based on the coding sequence for the 5HT-S2 receptor. The track was generated in a way that sounds similar to Takahashi’s and Miller’s method:
The number and nature of bass notes per codon/bar were determined by the hydrophobicity/hydrophilicity, ionic charge (positive or negative) and size of each amino acid residue (Proline, for example,which has no characteristics other than its small size, can be identified easily as the bars where the bass line ‘drops out’). The musical output resulting from these rules was further processed by mapping the notes onto different tonalities, both to make the piece more interesting, and to suggest the organisation of the protein molecule into regions of different secondary structure (although since S2 is a membrane protein and thus impossible to crystallise outside the lipid bilayer, this was definitely creative licence).
Previous pieces of DNA music have tended to sound unmelodic, because they often contain jump distances of up to two octaves (16 notes) from one tone to another. Takahashi and Miller overcame this by assigning three notes to each codon. With a triad chord for each codon, the differences between successive chords in the music are reduced.