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Table 5. Possible combinations of duration and pitch information, according to the absolute or relative
representation and on the levels of quantization
Duration
Abs.
Rel.
1
N
∞
1
N
∞
1
---
IOI
A
b
s.
P
i
t
c
h
N
∞
1
---
R
e
l.
N
PIT
BTH
∞
format downloaded from the Web. As for any test
collection, documents may contain errors. In a
preprocessing step, the channels containing the
melody have been extracted automatically and
the note durations have been normalized; in case
of polyphonic scores, the highest pitch has been
chosen as part of the melody. After preprocessing,
the collection contained 107 complete melodies
with an average length of 244 notes, ranging from
89 of the shortest melody to 564 of the longest.
Indexes were built on complete melodies, because
repetitions are important for the DD approach to
melodic segmentation. A set of 40 queries has
been created by randomly selecting 20 themes in
the dataset and using the first notes of the chorus
and of the refrain. The initial note and the length
of each query were chosen to have recognizable
motifs that could be considered representative of
real users' queries. The queries had an average
length of 9.75 notes, ranging from 4 to 21 notes.
Only the theme from which the query was taken
was considered as relevant.
the DD approach, lexical units may be different
from an index to the other, because IOI patterns
may not correspond to PIT or BTH patterns, and
vice versa.
It can be noted that any combination reported in
the table, eventually varying quantization, can be
used to index music documents from melodic in-
formation. An extensive evaluation of the retrieval
effectiveness of any combination of choice—and
their merging with data fusion techniques—has
not been carried out yet. The individual indexing
schemes can be fused in any combination. In the
presented evaluation, two data fusion approaches
have been tested: Fuse2 that merges the results
from PIT and IOI, and Fuse3 that merges all three
indexing schemes.
experimental evaluation
The effect of data fusion has been tested on a
small test collection of popular music, which has
been created using 107 Beatles' songs in MIDI
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