Abstract
Chord progressions play an important role in Western tonal music. For a novice composer, the creation of chord progressions can be challenging because it involves many subjective factors, such as the musical context, personal preference and aesthetic choices. This work proposes ChordAIS, an interactive system that assists the user in generating chord progressions by iteratively adding new chords. At each iteration a search for the next candidate chord is performed in the Tonal Interval Space (TIS), where distances capture perceptual features of pitch configurations on different levels, such as musical notes, chords, and scales. We use an artificial immune system (AIS) called opt-aiNet to search for candidate chords by optimizing an objective function that encodes desirable musical properties of chord progressions as distances in the TIS. Opt-aiNet is capable of finding multiple optima of multi-modal functions simultaneously, resulting in multiple good-quality candidate chords which can be added to the progression by the user. To validate ChordAIS, we performed different experiments and a listening test to evaluate the perceptual quality of the candidate chords proposed by ChordAIS. Most listeners rated the chords proposed by ChordAIS as better candidates for progressions than the chords discarded by ChordAIS. Then, we compared ChordAIS with two similar systems, ConChord and ChordGA, which uses a standard GA instead of opt-aiNet. A user test showed that ChordAIS was preferred over ChordGA and Conchord. According to the results, ChordAlS was deemed capable of assisting the users in the generation of tonal chord progressions by proposing good-quality candidates in all the keys tested.

Abstract
This article presents MixMash, an interactive tool which streamlines the process of music mashup creation by assisting users in the process of finding compatible music from a large collection of audio tracks. It extends the harmonic mixing method by Bernardes, Davies and Guedes with novel degrees of harmonic, rhythmic, spectral, and timbral similarity metrics. Furthermore, it revises and improves some interface design limitations identified in the former model software implementation. A new user interface design based on cross-modal associations between musical content analysis and information visualisation is presented. In this graphic model, all tracks are represented as nodes where distances and edge connections display their harmonic compatibility as a result of a force-directed graph. Besides, a visual language is defined to enhance the tool's usability and foster creative endeavour in the search of meaningful music mashups.

Abstract
In this paper we present Qualia, a software for real-time generation of graphical scores driven by the audio analysis of the performance of a group of musicians. With Qualia, the composer analyses and maps the flux of data to specific score instructions, thus, becoming part of the performance itself. Qualia is intended for collaborative performances. In this context, the creative process to compose music not only challenges musicians to improvise collaboratively through active listening, as typical, but also requires them to interpret graphical instructions provided by Qualia. The performance is then an interactive process based on “feedback” between the sound produced by the musicians, the flow of data managed by the composer and the corresponding graphical output interpreted by each musician. Qualia supports the exploration of relationships between composition and performance, promoting engagement strategies in which musicians participate actively using their instrument. © 2017 Manuel Brásio et al. This is an open-access article dis- tributed under the terms of the Creative Commons Attribution License 3.0 Unported, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract
In this article we present beatings, a web application for the exploration of tuning and temperaments which pays particular attention to auditory phenomena resulting from the interaction of the spectral components of a sound, and in particular to the pitch fusion and the amplitude modulations occurring between the spectral peaks a critical bandwidth apart. By providing a simple, yet effective, visualization of the temporal evolution of this auditory phenomena we aim to foster new research in the pursuit of perceptually grounded principles explaining Western tonal harmonic syntax, as well as provide a tool for musical practice and education, areas where the old art of musical tunings and temperaments, with the notable exception of early music studies, appears to have long been neglected in favour of the practical advantages of equal temperament. Copyright: © 2016 Rui Penha et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 Unported License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract
This paper describes a novel framework for real-time sonification of surface textures in virtual reality (VR), aimed towards realistically representing the experience of driving over a virtual surface. A combination of capturing techniques of real-world surfaces are used for mapping 3D geometry, texture maps or auditory attributes (aural and vibrotactile) feedback. For the sonification rendering, we propose the use of information from primarily graphical texture features, to define target units in concatenative sound synthesis. To foster models that go beyond current generation of simple sound textures (e.g., wind, rain, fire), towards highly “synchronized” and expressive scenarios, our contribution draws a framework for higher-level modeling of a bicycle's kinematic rolling on ground contact, with enhanced perceptual symbiosis between auditory, visual and vibrotactile stimuli. We scanned two surfaces represented as texture maps, consisting of different features, morphology and matching navigation. We define target trajectories in a 2-dimensional audio feature space, according to a temporal model and morphological attributes of the surfaces. This synthesis method serves two purposes: a real-time auditory feedback, and vibrotactile feedback induced through playing back the concatenated sound samples using a vibrotactile inducer speaker. Copyright: © 2019 Eduardo Magalhães et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 Unported License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract
Never The Less is a live audio-visual (A/V) networked performance, where participants are able to interact remotely and collaboratively. It adopts the newly-proposed web-based A/V Akson system, designed for an internet infrastructure, which allows both musical and visual content generation and interaction across multiple devices in remote locations. The system was built with great emphasis on live-performance and human collaboration, where experts and non-experts (i.e., artists and public) exist at the same level.