improving music mood classification using lyrics, audio and social tags

CHAPTER 5: BUILDING A DATASET WITH TERNARY
INFORMATION
The experiments described in Chapter 4 need to be conducted against a ground truth dataset
with ternary information sources available: audio, lyrics and social tags. Audio and lyrics are
used to build the classifiers, while social tags are used for giving ground truth labels to examples
in the dataset. This chapter describes the process of collecting and preprocessing the data with
ternary information sources, as well as the process of building the ground truth dataset with
mood labels given by social tags.
5.1 DATA COLLECTION
5.1.1 Audio Data
Audio is the most difficult to obtain among all the three information sources, due to
intellectual property and copyright laws imposed on music materials. For this reason, data
collection for this research started from audio data accessible to the author. The author is
affiliated with the International Music Information Retrieval Systems Evaluation Laboratory
(IMIRSEL) where this dissertation research is conducted. The IMIRSEL is the host of MIREX
each year, and has accumulated multiple audio collections of significant sizes and diversity (see
Table 5.1). The audio data in this dissertation research were selected from the IMIRSEL
collections.
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