Duet for Synthesizers and Mobile Conductor (2013)

Duet for Synthesizers and Mobile Conductor is a piece composed and performed by John Keston in collaboration with David T Steinman who also performs in the piece as the mobile conductor. Steinman creates a real-time audiovisual score that is broadcast into the performance space from a remote location. This score consists of textural, atonal, and arrhythmic “sound features” produced with artifacts from Steinman’s apartment. The imagery and amplified sound become content within the music as it is interpreted through improvisations by the synthesist, John Keston. Keston accompanies the sound features while controlling three analogue synthesizers (Novation Bass Station II, Korg Monotribe, and Korg Volca Keys). This use of an audiovisual score is a means to harness the sensory influence of non-musical sounds and images in our environments, elevating these sources to compositional structures.

Duet for Synthesizers and Mobile Conductor was performed on November 7, 2013 at the Strange Attractors festival, St. Paul, Minnesota. This video was captured during a private performance made shortly after the public showing. The piece is the first in a series of new Duets by Keston made possible by a grant from the American Composers Forum with funds provided by the Jerome Foundation.

Duets Setup

The shot above shows the setup I chose to use for this project. Although it is possible to synchronize these instruments, for this piece I decided to run them independently creating poly-temporal accompaniment for the atemporal audio I received from Steinman’s mobile conducting. Multiple free-running clocks were involved. For example, on the Bass Station II there are two LFOs, BPM for the arpeggiator and sequencer, and the second oscillator can be routed to modulate the the filter frequency. Both the Monotribe and the Volca also have BPM for their sequencers and a free-running LFO. In addition the Volca and Memory Man delays produced unsynchronized repetitions. All of these independent time sources helped create chaotic, non-interlocking rhythms that mimic and/or contrast the audiovisual score.

Mobile Rig

The sound and video from the mobile conductor was broadcast via UStream using a Logitech Broadcaster camera. This technique makes it possible for the mobile conductor to choose content for the piece from anywhere with internet access and still perform in near real-time with the ensemble. This made our performances with DKO at Northern Spark 2013 and WAM Bash 2013 possible. It also means that the quality of the video and audio from the broadcast is limited. Other examples of Duets (Duet Under Bridge, Duet for Synthesizer and Spin Cycle, Duet for Synthesizer and Rail Cars) do not have this requirement and do-have/will-have better sound and video quality than the Instant Cinema series.

Novation Bass Station II Self Oscillating Filter Demo

I have recently been trying out a Novation Bass Station II monophonic analogue synthesizer. I am quite impressed with this big sounding synth in a small package. While digitally controlled, Novation have focused on packing in proper synthesis features rather than trying to gloss over the sound with onboard effects. For example, as I have illustrated in the video, the filter self oscillates nicely with a clean sine wave that can be modulated in unique ways especially with distinct features like oscillator slew.

The video starts with the self oscillating filter getting modulated by LFO 2 using the triangle wave. After that I switch to using the sample and hold setting creating the well-known 60s computer sound of random notes. Here’s where it gets interesting though. Once I switch the LFO to sample and hold I start turning up the oscillator slew I mentioned earlier. What this does is variably smooth the wave shapes created by the LFO. You’ll hear this come in at 0:28. It sounds like portamento. At 0:35 I switch the LFO to the square wave, but with the slew on it sounds more like a sine. As I reduce the amount of slew the square wave regains its recognizable character. Next I switch it to the saw tooth wave. The nice thing here is that the LFO amount can go into negative values allowing the saw to be reversed.

Another distinctive feature is the oscillator filter mod setting. This modulates the filter with oscillator 2. Since the oscillators range from subsonic to almost supersonic this feature offers modulation effects that are not possible with the LFOs. At 1:29 you will start to hear the oscillator filter mod come in using a pulse waveform. What makes this interesting is that while oscillator 2 is modulating the filter it can also have the pulse width modulated by LFO 1. This can cause bit-reduction-like effects that can be heard between 1:49 and 2:19. At 2:20 I start tapping the octave and waveform buttons on oscillator 2 illustrating what happens when the modulation source is instantly shifted an octave at a time. After a bit more messing around I added a final, manual filter sweep at 3:20.