Goldberg: Interfaces

The original Goldberg idea implied an interface in which Goldberg presents choices and the user auditions them and somehow rates them or chooses among them in order to guide the next set of variations Goldberg presents. In this kind of model, it is clear to the user that Goldberg is doing a lot of the work and that the user, to a certain extent, is a passive listener. This interface would tend to lump Goldberg with other "computer composition" or "algorithmic composition" tools, which might turn off the potential audience of traditional composers.

We therefore designed an interface similar to Goldberg but based upon a more traditional model of composing in which the composer writes out music and auditions the results. Most of the power of Goldberg is still available, but the composer is in total control of when and how operations are applied to create variations.

The three interfaces we tested (in the order presented to subjects) are:

• Rating. An interface based on repeatedly rating variations presented by Goldberg and then waiting for Goldberg to calculate new variations depending on your ratings.
• Choosing. An interface based on repeatedly choosing a single variation from a set presented by Goldberg and then waiting for Goldberg to present variations on that choice.
• Music Processor. An interface based on the idea of a word processor for music which provides operations for generating variations on a selected piece of music.

These interfaces represent a variety of answers to the questions we wish to explore.

• Rating vs. choosing (we also asked subjects about ranking, though we did not test it).
• Anonymous variations (in the Rating interface) vs. named variations (in the Choosing interface).
• Usefulness of visual representations:
  • The Rating interface had no visual representations.
  • The Choosing interface offered simple piano-roll depictions.
  • The Music Processor used musical notation.
• Degree of control over the process:
  • With the Rating interface, the composer is extremely passive, simply rating things.
  • With the Choosing interface, the composer explicitly chooses the direction of exploration and has more awareness of how variations are constructed.
  • With the Music Processor, the composer is in complete control, invoking Goldberg's operations explicitly.