Cat Lamb and I began meeting in the summer of 2009 to invent vocal experiments that address the question, “How do you sing in tune?” In tune can mean many different things, and in this case our reference point is the overtone series. How do soundwaves align and how can we train our ears to observe the necessary information to reproduce different intervals that are found in the overtone series? After a few months, we set out to continue our experiments with a larger number of people, which is now a group called Singing by Numbers. The more people there are singing, the better we can hear the cues to tune our voices, and also the more complex harmonies we can create.

Branches, written by Cat Lamb in late 2009, is the first actual composition that came out of our vocal experiments. It is a visual score that functions as a unique map for each singer. There are 16 tones from the overtone series that are available to be sung, with rules that govern how the tones can proceed from each other in time. All singers follow the same map, but the pace at which they travel and the forks/paths that are followed and when they are followed are all independent decisions. A primary goal of each singer is to listen carefully to how each tone they sing locks in to the tones sung by the other singers. Theoretically, all the tones in the piece align with each other because they are part of the same overtone series.

Because of the autonomy of each singer, dense harmonies are bound to arise from many tones being sung at the same time. Over the course of the piece, the number of available tones increases. There is a shifting density of tones throughout the piece, and natural widening and crescendo that occurs from beginning to end. This recording of Branches involved 12 women vocalists. It was performed at the wulf. in April 2010.

—Laura Steenberge

Additional voices: Jess Basta, Jessica Catron, Mari Garrett, Sascha Goldhor, Julia Holter, Cat Lamb, Heather Lockie, Jessie Rothwell, Laura Steenberge, Cassia Streb, Christine Tavolacci