La fressa d'en Glen

Glen’s Rumblings from Barcelona

Step on a Crack…

…but try to avoid doing any harm to your mother’s back.

For this piece, I took a map showing a small portion of the San Andreas fault, and mapped the fault lines into melodic and harmonic lines. The map was randomly assigned to me (see details of this 73rd Disquiet Junto project below). I programmed the score and instruments in SuperCollider, recorded three complete takes in real time, and finally mixed them together. Each part is different, because there is some random variation in the patterns. However, they are similar enough that they blend together well, like different musicians improvising to the same piece.

Map showing a small segment of the San Andreas fault, used as basis for “Step on a Crack”. Obtained from USGS via Disquiet Junto.

I started by importing a (hand-processed) map image containing only the relevant black lines, as a Portable Greymap (PGM) text file. Then, I created a series of SuperCollider patterns that read and indexed into this data, using it to pick degrees from different scales. The musical score moves from left to right through the image, taking the horizontal axis as time.

The solid and dashed black (fault-line) pixels are taken to represent “potential” eighth notes. There were 1500 columns across the original image, so there were about 188 4-beat bars in the piece. The tempo varies, though, between one bar per second and four seconds per bar. There can be more than one black line at any given time – since the faults bifurcate and merge – and these correspond to different voices. The lead voice comes from the “strongest” line, and is quite a simple tone with a percussive envelope. Beneath that are several analog-esque monophonic voices, plus extra hits at “geographically busy” places, using a synthesized plucked-string sound.

Pauses and modal changes were chosen manually, at points that seemed musically interesting.

Produced for Disquiet Junto Project 0073: Faulty Notation).

Instructions: This week’s project is about earthquakes. Each participant will receive a distinct section of a map of the San Andreas Fault. The section will be interpreted as a graphic notation score. The resulting music will, in the words of Geoff Manaugh of BLDG BLOG, “explore the sonic properties of the San Andreas Fault.”

There are 4 steps to this project:

Step 1: To be assigned a segment of the map, go to the following URL. You will be asked to enter your SoundCloud user name, and then to enter your email address. You will receive via that email address a file, approximately 1MB in size, containing your map segment.

Step 2: Study the map segment closely. Develop an approach by which you interpret the map segment as a graphic notation score. The goal is for you to “read” the image as if it were presented as a piece of notated music. Read the image from left to right. Pay particular attention to solid black lines, which represent fault lines. For additional guidance and inspiration, you may refer to the map legend at the following URL. The extent to which you take the legend into consideration is entirely up to you.

Step 3: Record an original piece of music based on Step 2. It should be between two and six minutes in length. You can use any instrumentation you choose, except the human voice. (Note: Do not use any source material to which you do not yourself outright possess the copyright. This is highly important, because we may look into developing a free iOS app of the resulting recordings.)

Step 4: When posting your track, include a description of your process in planning, composing, and recording it. This description is an essential element of the communicative process inherent in the Disquiet Junto.