An Expert System Devoted to Automated Music Identification and Recognition - Intelligent Music Information Systems: Tools and Methodologies - page 89

For instance, the first and the fourth of these
production rules respectively mean:

characteristics of a musical style but rather, they
are like valuations assigned to subsets of the sets
of the characteristics A, D, … and H, in such a
way that these valuations are approximations to
the final identification of one of the three styles
(or of no style at all).

“IF regular structures = yes AND major
tones = yes THEN Classic structure”

“IF regular structures = yes AND major
tones = no AND sumptuousity = no THEN
Classic structure”

first second-level table

Let us denote by S1, S2, S3 and S4, the expres-
sions “first approach to identification = Baroque”,
“first approach to identification = Rococo”, “first
approach to identification = Classic”, “first ap-
proach to identification = none of these styles”.
The combinations of the A, B, D and E, give rise
to Table 4.
For instance, two of the 162 second-level pro-
duction rules corresponding to this table are:

• The combinations of X22, X23 and their

contraries give rise to the literals I1, I2,
I3 and I4, which represent the Baroque,
Rococo, Classic and “none of these styles”'
composition , respectively.

second level production rules

The literals A, D, E, F, G, H and I (each one hav-
ing four elements, as A1, A2, A3, and A4 for A)
are, on their side, arranged (by the experts!) into
three tables, one for the A, B, D and E, one for
the F, G and C, and one for H and I. Each of these
three tables gives rise to a set of four literals each:
{S1,...,S4}, {T1,...,T4} and {V1,...,V4}, respectively.
These three sets of four literals are not particular

A1 ^ B1 ^ E1 ^ D1 → S1
A3 ^ B2 ^ E3 ^ ¬D1 → S2

which, respectively, mean

“IF Baroque tendency_I = yes AND Baroque
characteristics = yes

Table 4. First second-level table (note that first level rules lead neither to ¬D2 nor to ¬ D4, so they do
not appear as input in this table)

E1 E1 E1 E1 E1 E1 E2 E2 E2 E2 E2 E2 E3 E3 E3 E3 E3 E3

D1 ¬D1 D2 D3 ¬D3 D4 D1 ¬D1 D2 D3 ¬D3 D4 D1 ¬D1 D2 D3 ¬D3 D4

A1 B1 S1 S1 S1 S4 S1 S4 S1 S2 S2 S2 S2 S4 S4 S4 S4 S4 S4 S4

A1 B2 S1 S2 S1 S4 S2 S4 S1 S2 S2 S4 S2 S4 S4 S2 S2 S2 S2 S4

A1 B3 S1 S2 S2 S4 S2 S4 S2 S2 S2 S4 S4 S4 S4 S3 S2 S3 S3 S4

A2 B1 S1 S2 S2 S4 S2 S4 S2 S2 S2 S4 S2 S4 S2 S4 S4 S2 S4 S4

A2 B2 S1 S2 S2 S4 S2 S4 S2 S2 S2 S2 S2 S4 S2 S4 S2 S2 S2 S4

A2 B3 S2 S4 S3 S4 S4 S4 S4 S2 S2 S2 S2 S4 S2 S2 S2 S3 S2 S4

A3 B1 S2 S4 S4 S4 S4 S4 S4 S2 S2 S4 S2 S4 S4 S4 S4 S3 S4 S4

A3 B2 S2 S4 S4 S4 S4 S4 S4 S2 S2 S2 S2 S4 S4 S2 S2 S3 S4 S4

A3 B3 S4 S4 S4 S4 S4 S4 S2 S3 S2 S3 S4 S4 S4 S3 S3 S3 S4 S4