An Expert System Devoted to Automated Music Identification and Recognition - Intelligent Music Information Systems: Tools and Methodologies - page 86

plus some use of chord. In this style, music com-
positions begun to have harmonic complexity. It
is plenty of contrasts and importance is given to
motif as well as to phrase.
Classicism identifiers are: equilibrium, clear-
ness, regularity, simplicity, proportion, delicate-
ness, beautifulness, brightness, reflects happiness
and naturality, has bass Alberti, it uses metal wind
instruments, importance is given to phrase and in
many cases was devoted to the Royal Courts.

The elements of F that the user judges that
apply to the score under study are introduced as
“Xi” (i = 1, 2, 3, …, 23) and those the user judges
the score does not have are introduced as “not-Xj”
(j = 1, 2, 3, …, 23).
We have divided the 23 pairs in F into five
classes. For instance, X1 (which means religious),
X2 (solemn) and X3 (sumptuous), together with
X4 (finesse) and X5 (seemingly devoted to small
selected audiences as Royal Courts) constitute,
together with their negations, the class to be named
“ musical-related characteristics of epoch ”;
X14 (motif), X15 (phrase), X16 (bass Alberti),

construction of the knowledge Base

As said above, all KB consist of a rule base RB
and a fact base F. Although we said above that the
elements of F are both the literals that are in the
antecedents but not in any of the consequents of
any of the production rules and their contraries,
this does not mean that we must have the RB
constructed before constructing F. Rather, as will
be seen next, F is usually built first.

Table 1. Classification of the potential facts

Musical-Related Characteristics of the Epoch
X1- Religious
X2- Solemn
X3- Sumptuous
X4- Finesse
X5- Seemingly devoted to a selected audience, like Royal Courts
Instrumentation
X6- Wood wind instruments plus trumpet
X7- Chord
X8- Remainder wind-chord
Characteristics of the Musical Style
X9- Proportion.
X10- Harmonic complexity
X11- Contrasts
X12- Clearness
X13- Equilibrium
Components of the Structure of the Music Work
X14- Motif
X15- Phrase.
X16- Alberti bass
X17- Continuous bass
X18- Melody
Compositional Analysis
X19- Regular structures
X20- Major tones
X21- Ornamentation
X22- Polyphonic development or counter point
X23- Melody accompaniment

description of the set f of potential
facts

The set F of potential facts consists of 23 + 23
elements (23 elements X1, X2, …, X23, and 23
elements not-X1, not-X2, …, not-X23). These
elements, according to the opinion of the experts
consulted, are the most relevant music identifiers
which are present in the musical styles studied
in this chapter.
As it will be seen, the RB of ES1, once con-
structed, remains unchanged, while each score
under study by ES1 (the same would happen in
ES2 and ES3) is characterized by just one subset
A of F, each A consisting of 23 elements of F.
Each one of the mentioned subsets A of F is a
maximal consistent subset of the whole set F:
“consistent” means that from each pair formed
by a potential fact and its contrary at most one
element of the pair is chosen (otherwise, a same
style would be described by two contrary facts)
and “maximal” means that such a selection must
be done for all pairs.