Current Challenges and Visions in Music Recommender Systems Research

Music recommender systems (MRS) have experienced a boom in recent years, thanks to the emergence and success of online streaming services, which nowadays make available almost all music in the world at the user's fingertip. While today's MRS considerably help users to find interesting music in these huge catalogs, MRS research is still facing substantial challenges. In particular when it comes to build, incorporate, and evaluate recommendation strategies that integrate information beyond simple user--item interactions or content-based descriptors, but dig deep into the very essence of listener needs, preferences, and intentions, MRS research becomes a big endeavor and related publications quite sparse. The purpose of this trends and survey article is twofold. We first identify and shed light on what we believe are the most pressing challenges MRS research is facing, from both academic and industry perspectives. We review the state of the art towards solving these challenges and discuss its limitations. Second, we detail possible future directions and visions we contemplate for the further evolution of the field. The article should therefore serve two purposes: giving the interested reader an overview of current challenges in MRS research and providing guidance for young researchers by identifying interesting, yet under-researched, directions in the field

Measuring the Eccentricity of Items

The long-tail phenomenon tells us that there are many items in the tail. However, not all tail items are the same. Each item acquires different kinds of users. Some items are loved by the general public, while some items are consumed by eccentric fans. In this paper, we propose a novel metric, item eccentricity, to incorporate this difference between consumers of the items. Eccentric items are defined as items that are consumed by eccentric users. We used this metric to analyze two real-world datasets of music and movies and observed the characteristics of items in terms of eccentricity. The results showed that our defined eccentricity of an item does not change much over time, and classified eccentric and noneccentric items present significantly distinct characteristics. The proposed metric effectively separates the eccentric and noneccentric items mixed in the tail, which could not be done with the previous measures, which only consider the popularity of items.Comment: Accepted at IEEE International Conference on Systems, Man, and Cybernetics (SMC) 201

Conformity, deformity and reformity

In any given field of artistic practice, practitioners position themselves—or find themselves positioned—according to interests and allegiances with specific movements, genres, and traditions. Selecting particular frameworks through which to approach the development of new ideas, patterns and expressions, balance is invariably maintained between the desire to contribute towards and connect with a particular set of domain conventions, whilst at the same time developing distinction and recognition as a creative individual. Creativity through the constraints of artistic domain, discipline and style provides a basis for consideration of notions of originality in the context of activity primarily associated with reconfiguration, manipulation and reorganisation of existing elements and ideas. Drawing from postmodern and post-structuralist perspectives in the analysis of modern hybrid art forms and the emergence of virtual creative environments, the transition from traditional artistic practice and notions of craft and creation, to creative spaces in which elements are manipulated, mutated, combined and distorted with often frivolous or subversive intent are considered. This paper presents an educational and musically focused perspective of the relationship between the individual and domain-based creative practice. Drawing primarily from musical and audio-visual examples with particular interest in creative disruption of pre-existing elements, creative strategies of appropriation and recycling are explored in the context of music composition and production. Conclusions focus on the interpretation of creativity as essentially a process of recombination and manipulation and highlight how the relationship between artist and field of practice creates unique creative spaces through which new ideas emerge

The Constructivistly-Organised Dimensional-Appraisal (CODA) Model and Evidence for the Role of Goal-directed Processes in Emotional Episodes Induced by Music

The study of affective responses to music is a flourishing field. Advancements in the study of this phenomena have been complemented by the introduction of several music-specific models of emotion, with two of the most well-cited ones being the BRECVEMA and the Multifactorial Process Model. These two models have undoubtedly contributed to the field. However, contemporary developments in the wider affective sciences (broadly described as the ‘rise of affectivism’) have yet to be incorporated into the music emotion literature. These developments in the affective sciences may aid in addressing remaining gaps in the music literature, in particular for acknowledging individual and contextual differences. The first aim of this thesis was to outline contemporary theories from the wider affective sciences and subsequently critique current popular models of musical emotions through the lens of these advancements. The second aim was to propose a new model based on this critique: the Constructivistly-Organised Dimensional-Appraisal (CODA) model. This CODA model draws together multiple competing models into a single framework centralised around goal-directed appraisal mechanisms which are key to the wider affective sciences but are a less commonly acknowledged component of musical affect. The third aim was to empirically test some of the core hypotheses of the CODA model. In particular, examining goal-directed mechanisms, their validity in a musical context, and their ability to address individual and contextual differences in musically induced affect. Across four experiments which include exploratory and lab-based designs through to real- world applications, the results are supportive of the role of goal-directed mechanisms in musically induced emotional episodes. Experiment one presents a first test battery of multiple appraisal dimensions developed for music. The results show that several of the hypothesised appraisal dimensions are valid dimensions is a musical context. Moreover, these mechanisms cluster into goal-directed latent variables. Experiment two develops a new set of stimuli annotations relating to musical goals, showing that music can be more or less appropriate for different musical goals (functions). Experiment three, using the new stimuli set from experiment two, tests the effects of different goals with more or less appropriate music on musically induced affect. These results show that goal-directed mechanisms can change induced core-affect (valence and arousal) and intensity, even for the same piece of music. Experiment four extends the study of goal-directed mechanisms into a real-world context through an interdisciplinary and cross-cultural design. The final experiment demonstrates how goal-directed mechanisms can be manipulated through different algorithms to induce negative affect in a Colombian population. The main conclusions of this thesis are that the CODA model, more specifically goal-directed mechanisms, provide a valuable, non-reductive, and more efficient approach to addressing individual and contextual differences for musically induced emotional episodes in the new era of affectivism

A collaborative filtering method for music recommendation

Dissertation presented as the partial requirement for obtaining a Master's degree in Data Science and Advanced AnalyticsThe present dissertation focuses on proposing and describing a collaborative filtering approach for Music Recommender Systems. Music Recommender Systems, which are part of a broader class of Recommender Systems, refer to the task of automatically filtering data to predict the songs that are more likely to match a particular profile. So far, academic researchers have proposed a variety of machine learning approaches for determining which tracks to recommend to users. The most sophisticated among them consist, often, on complex learning techniques which can also require considerable computational resources. However, recent research studies proved that more simplistic approaches based on nearest neighbors could lead to good results, often at much lower computational costs, representing a viable alternative solution to the Music Recommender System problem. Throughout this thesis, we conduct offline experiments on a freely-available collection of listening histories from real users, each one containing several different music tracks. We extract a subset of 10 000 songs to assess the performance of the proposed system, comparing it with a Popularity-based model approach. Furthermore, we provide a conceptual overview of the recommendation problem, describing the state-of-the-art methods, and presenting its current challenges. Finally, the last section is dedicated to summarizing the essential conclusions and presenting possible future improvements

Microsaccade-rate indicates absorption by music listening

The power of music is a literary topos, which can be attributed to intense and personally significant experiences, one of them being the state of absorption. Such phenomenal states are difficult to grasp objectively. We investigated the state of musical absorption by using eye tracking. We utilized a load related definition of state absorption: multimodal resources are committed to create a unified representation of music. Resource allocation was measured indirectly by microsaccade rate, known to indicate cognitive processing load. We showed in Exp. 1 that microsaccade rate also indicates state absorption. Hence, there is cross-modal coupling between an auditory aesthetic experience and fixational eye movements. When removing the fixational stimulus in Exp. 2, saccades are no longer generated upon visual input and the cross-modal coupling disappeared. Results are interpreted in favor of the load hypothesis of microsaccade rate and against the assumption of general slowing by state absorption

Recordings as learning and practising resources for performance: exploring attitudes and behaviours of music students and professionals

This article examines how musicians use recordings as learning resources in preparing for performance. While previous research has partially acknowledged the contribution of external factors to self-regulated learning, the specific impact of recordings on performers’ approaches to practising remains largely uncharted. A survey was designed to assess the use and importance of recordings on musicians’ listening and practising behaviours, their preferences when choosing recordings, and the type of influence exerted by recordings over self-regulatory processes. Respondents (N = 204) completed an online survey, and the data were analysed according to level of expertise: advanced music students (n = 147) and professional musicians (n = 57). The results show clear differences between students and professionals in the frequency of use and level of reliance on recordings, with students consistently exhibiting a greater preference for these resources. Students were more likely to listen to recordings and, consequently, change aspects of their interpretations in the early stages of practising. Additionally, students were influenced by other people’s recommendations, especially their teachers’, and by other performers’ reputations when choosing recordings. The need to develop a distinct style had a positive influence on students’ practising and performing habits. The study shows that listening to recordings forms an integral part of self-regulated learning activities and contributes to musicians’ development by increasing musical knowledge and stylistic awareness