Home SpannerLogo XOrch: Real-time Orchestration


Here is the XOrch (expressed orchestration) view of the same Perf shown on the PerfEditor page. The small green box near top of the display is a cursor that shows the position of the XOrch pedal. It moves horizontally as you press the pedal.

Directly below it is a multicolored bar, the zone bar, that sums all the other bars below it into one. When practicing or playing you mainly watch the cursor and pedal it into zones defined by this zone bar.

Moving the cursor to the far left of this screen puts XOrch into the initial red zone. This causes the system to play only on the Electric Piano and the Harp instruments.

By depressing the pedal more the cursor can be driven into the next zone to the right, the initial purple zone. This brings the Cello instrument into the mix.

Pressing the pedal all the way down sends the cursor to the far right and brings all the instruments, except the Cello, into the mix.

XOrch action is very fast. You can hear the speed of the drastic orchestration changes in the YouTube demos.

To use XOrch you need a pedal that puts out continuous values from 0 to 127.

Our XOrch function interacts with the Sustain and the Sostenuto pedals to produce nice mixes of differing orchestration levels. This is hard to explain simply but you can hear it in the demos. Even though XOrch does not put out any harmony, only unisons offset by octaves, nevertheless harmonic passages are easily achieved. XOrch is new and novel, we think. XOrch can also be controlled by a slider. It's just a CC. Those driving Spanner with a sequencer might prefer it. If you drive it with a sequencer also use a Sustain pedal, or switch.


Tips on use.

There are mainly two ways to set up Perfs for XOrch. One is where you want to be able to pedal between drastically different ensemble sounds. An example of this is the youtube demo "Don't Get Around Much". In it you hear the performer switch back and fourth between these 5 ensembles:

  • at 0-21: Vibes, piano, bass, & drums (Pedal is all the way up)
  • at 22-69: Soft saxes, bass & drums
  • at 70-103: Soft brass, bass & drums
  • at 104-113: Loud brass, String ensemble, bass & drums
  • at 114-127: Loud brass, Loud Saxes, String ensemble, bass & drums (Pedal is all the way down)


  • DontGetAroundMuch XOrch


    The other main use of XOrch is to go from a solo instrument or core group sound, by stages, to a largely instrumented sound. The youtube demo "Tango" is a simple example of this.

    Tango XOrch


    A basic technique with the "Tango" style performance is to pull the pedal up to zero when playing melody notes then quickly depressing the pedal back down when playing fills. The Sustain pedal is then held down while playing next bit of melody so that the fills sound as harmony. Repeat this as piece progresses. (Of course we have to drop sustain soon as chords change enough, so it's not quite so simple.)

    Another basic technique is to set up transition sounds so you can hear where you are with the pedal. For instance, when going from an ensemble that is piano and strings forward towards one including brass you might have just the French Horn come in a little before the full brass section. As you slowly depress the pedal you can position exactly on the verge of the next big ensemble change so you can get an accurate dramatic entrance.

    The best XOrch pedal would be one that has a large movement range. Simple volume control pedals are inadequate. The youtube demos currently posted used a Fatar VP26U pedal which puts out 0-127 in midi values with the first non-zero value being 21. Some volue controls put out around 70 as the first non-zero value. This Fatar pedal is barely adequate but costs around $25.