Autoconductor

Synchronizing graphic scores, multi-channel sound and full-HD projection

Summary

Autoconductor is a networked score display system which synchronizes graphical notation, precise notation and video with multi-channel audio. The software was purpose built for the project The Glacier - Opera 2.0.

1. Hardware

a) Server site:

(1) Computer

A computer is necessary on which the software "Autoconductor" is installed. Minimum system requirements: 3rd generation CPU i3 with 4GB ram. At the moment the software "Autoconductor" only runs on Linux. A conversion to other operating systems is planned.

(2) Video

A projector for the audience should be connected to the computer.

(3) Audio

An audio interface with 8 outputs is required. If the audio interface has less than 8 outputs, the channels should be routed with "Jack" (https://jackaudio.org) instead of the standard Linux sound server "Alsa" because “Alsa” otherwise mixes channel 3 with channels 1 and 2.

If everything is routed correctly, it should look like this: Channels 1 and 2 together form a stereo track. These go to the loudspeakers that are directed to the audience. Channel 3 is the click track. No other channels were used in this composition, that means channels 4-8 are muted.

(4) Router

A router is connected via the LAN output of the computer, which streams the local "Autoconductor" website containing the graphic notations via WIFI.

b) Client site

The musicians read the score from a screen. Most devices (Android, Windows, iOS, macOS, etc.) with an integrated web browser will work.

2. Software

a) Server site

Autoconductor is a networked score display system which synchronizes graphical notation, precise music notation and video with multi-channel audio. The software was purpose built for the project “The Glacier - Opera 2.0”.

The video playback is controlled by an application with a graphical user interface that runs on the server:

To keep the setup time for the musicians as low as possible, a single web page provides the entire content. Except for an initial drop-down box to select the score for the instrument at hand, there is no further control element on the page.

The content is provided and controlled by the server, the client-side technique used to display the scores is JavaScript and the communication is done via websockets.

b) Client Site

The client side is a single web page, the initial view shows a drop-down box to select the instrument or track. Once selected, the drop-down box is hidden. A cursor (black vertical line) appears on the graphic. The cursor indicates the actual position. The scrolling in this graphical score runs from right to left.

c) Conductor

(1) Screen and score

The conductor is the only one who sees the complete score. The musicians receive a video stream with only their individual part below the graphic, which is the same for everyone. The score length on the sketch paper is 40 cm per page. It takes 40 seconds to perform one page.

Since the size of the screen in landscape format is not sufficient, the notes of only one instrument can currently be displayed under the graphic. Therefore, in addition to the selected instrument on the screen, the conductor must also follow the score.

(2) Click track

A headphone for the conductor is required for the click track. The click track in the different passages is always prepared by 2 bars of pre-counting.

Before the rehearsal, the app was tested with 12 devices:

Conclusion

Of course a human conductor is indispensable for the rehearsals, for the development of the work and for the first performances. But at the concerts in New York our conductor could not come along. But thanks to the autoconductor software, the performances were possible without a human conductor: