Experiments in Musical Intelligence
Take-home exam for CS256, Fall 2001
Name______________________
Directions. Please limit your answers to a few sentences, don’t write essays. The exam is
due on Wednesday, Nov. 28.
1. Prof. Cope told us that there is no artificial intelligence in EMI, “it just computes”.
On page 5 of the textbook there are several definitions of AI. Pick one of these
definitions and explain why, according to that definition, EMI is or is not artificially
intelligent. Please limit your answer to a few sentences, don’t write an essay.
2. There are rules in music theory books for composing Bach-style chorales, and music
theory students are given the task of composing using those rules. Cope mentioned as
an example that the main melody line should move up or down by small steps, while
the bass line may take larger jumps. EMI’s Bach-style chorales follow these rules,
without the rules having been programmed into EMI. How does that happen? Make
sure your explanation accounts for the specific example given. Answer this based
on very general principles about EMI, not on technical details.
3. By a “grammatical” analysis, EMI extracts patterns (in the examples usually just one
or a few measures long) from input musical compositions. How does it use these
patterns to extract a description of the input music’s style? What is the form of that
description or representation?
4. Once the description of style as in question 3 has been extracted from the input data, is
the input data used any further for the generation of new music?
5. Does EMI make any use of probabilistic methods? More precisely, are there places
in EMI where floating-point numbers extracted from input data are used as
probabilities to help determine what music comes next?
6. On page 53 of the handout from Experiments in Musical Intelligence, there is an
example of gradually filling in words in a grammatical template, with the implication
that this is analogous to how EMI creates music. But, as you know from your study
of natural language processing, most ways of filling in such a template would be
nonsensical--not pleasing sentences like the example. How does EMI avoid
producing nonsensical musical examples if it fills in a grammatical template in an
analogous way (e.g. Fig. 2.17 and 2.18 in that handout)?
7. One of the handouts discussed the “controller” parameters used in EMI’s patternmatching algorithm. In general each parameter can be set “looser” (more tolerance)
or “tighter” (less tolerance). What would happen to the composition process (and/or
the resultant music) if the parameters were set too “loosely”? If they are set too
“tightly”?