Crumar Spirit

The Crumar Spirit. This unit is owned by one of its co-designers, Dr. Thomas L. Rhea, the eminent historian of electronic music who suggested many of the Spirit’s very unique and unusual features.

The Crumar Spirit is a portable, hardwired (non-modular), analog, monophonic, live performance synthesizer designed in 1981 for the Italian company Crumar by a special collaboration involving Dr. Robert Moog, the inventor of the Moog Synthesizer,; Dr. Tom Rhea, electronic music historian and synthesis expert; and Jim Scott, former Moog synthesizer engineer. In a nutshell, Moog arranged and oversaw the contract, Rhea suggested many of the features, and Scott designed the actual electronics.

The Spirit is, in a phrase, one of the most unusual and interesting analog synthesizers ever created. Among other things it features two different modulation sections, band-pass and high-pass filtering, formant (fixed) filtering, an amazingly clever sequencer, ring modulation, and a multipath architecture.

I was fortunate to have encountered this wonderful instrument at EMEAPP, the Electronic Music Education And Preservation Project, and separately at the home of Thomas L. Rhea. I was deeply inspired by its sound, and created the following two pieces, which demonstrate some of the capabilities of this remarkable instrument. These are called Spirit of Synthesis I & II. The first one is incomplete, as this was a first try that was abandoned due to some technical problems with the instrument that were subsequently corrected in preparation for the second piece, although I still like the sounds contained therein.

In any case, the improvisational aspects of these pieces were both new for me:

  • First, in both cases I first created some tracks using the Spirit’s very unique and powerful arpeggiator. This arpeggiator enables one to generate unusually complex patterns of notes by holding down various clusters of notes. One can hear these sequences in both tracks.
  • In the second piece I then experimented by improvising a series of similar but different lines over the arpeggiator tracks. I did this one at a time, without listening to the others at the same time. And then I experimented with layering them over one another, shifting the pieces back in forth in time, which is possible due to the fact that there are no underlying chord changes to keep in sync with. I had never taken this approach before, but found that it could create a remarkably coherent whole.

Aspects of the Spirit utilized in this recording include:

  • The Spirit’s arpeggiator, as mentioned above: The arpeggiator drives the background pattern of triangle wave notes. The finger pattern was varied continuously. All three modes of the arpeggiator were used, in sequence, and then reverting to 2 and then 3 again.
  • The noise source with two resonance peaks varied independently.
  • Sample & hold driven ring modulator.
  • Sawtooth bass drone with Minimoog-like timbre and resonant filter sweeps.
  • Minimoog-like triangle wave patch played with the Spirit’s arpeggiator in “LEAP” mode.
  • Formant filtering of the brass like voice, and bandpass filtering of the nasal voice.
  • Note: No EQ was applied. The only effect utilized was a digital spring reverb, uniformly used on all voices. Recorded with Logic Pro X.

Spirit of Synthesis I:

Spirit of Synthesis II: