558 research outputs found

    Spectral pitch distance and microtonal melodies

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    We present an experiment designed to test the effectiveness of spectral pitch distance at modeling the degree of “affinity” or “fit” of pairs of successively played tones or chords (spectral pitch distance is the cosine distance between salience-weighted, Gaussian-smoothed, pitch domain embeddings of spectral pitches—typically the first eight to ten partials of a tone). The results of a previously conducted experiment, which collected ratings of the perceived similarity and fit of root-position major and minor triads, suggest the model works well for pairs of triads in standard 12-tone equal temperament tunings. The new experiment has been designed to test the effectiveness of spectral pitch distance at modeling the affinity of tones in microtonal melodies where the partials of the tones can be variably tempered between being perfectly harmonic and perfectly matched to the underlying microtonal tuning. The use of microtonal tunings helps to disambiguate innate perceptual (psychoacoustical) responses from learned (cultural) responses. Participants are presented with a software synthesizer containing two unlabeled controls: one adjusts the precise tuning of the tones; the other adjusts the extent to which the spectrum is tempered to match the tuning (as set by the first control). A selection of microtonal melodies are played in different tunings, and the participants adjust one, or both, controls until they find a “sweet spot” at which the music sounds most “in-tune” and the notes best “fit” together. The results of these experiments will be presented and discussed

    Hex Player—a virtual musical controller

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    In this paper, we describe a playable musical interface for tablets and multi-touch tables. The interface is a generalized keyboard, inspired by the Thummer, and consists of an array of virtual buttons. On a generalized keyboard, any given interval always has the same shape (and therefore fingering); furthermore, the fingering is consistent over a broad range of tunings. Compared to a physical generalized keyboard, a virtual version has some advantages—notably, that the spatial location of the buttons can be transformed by shears and rotations, and their colouring can be changed to reflect their musical function in different scales. We exploit these flexibilities to facilitate the playing not just of conventional Western scales but also a wide variety of microtonal generalized diatonic scales known as moment of symmetry, or well-formed, scales. A user can choose such a scale, and the buttons are automatically arranged so their spatial height corresponds to their pitch, and buttons an octave apart are always vertically above each other. Furthermore, the most numerous scale steps run along rows, while buttons within the scale are light-coloured, and those outside are dark or removed. These features can aid beginners; for example, the chosen scale might be the diatonic, in which case the piano’s familiar white and black colouring of the seven diatonic and five chromatic notes is used, but only one scale fingering need ever be learned (unlike a piano where every key needs a different fingering). Alternatively, it can assist advanced composers and musicians seeking to explore the universe of unfamiliar microtonal scales

    Wide-Field-of-View, High-Resolution, Stereoscopic Imager

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    A device combines video feeds from multiple cameras to provide wide-field-of-view, high-resolution, stereoscopic video to the user. The prototype under development consists of two camera assemblies, one for each eye. One of these assemblies incorporates a mounting structure with multiple cameras attached at offset angles. The video signals from the cameras are fed to a central processing platform where each frame is color processed and mapped into a single contiguous wide-field-of-view image. Because the resolution of most display devices is typically smaller than the processed map, a cropped portion of the video feed is output to the display device. The positioning of the cropped window will likely be controlled through the use of a head tracking device, allowing the user to turn his or her head side-to-side or up and down to view different portions of the captured image. There are multiple options for the display of the stereoscopic image. The use of head mounted displays is one likely implementation. However, the use of 3D projection technologies is another potential technology under consideration, The technology can be adapted in a multitude of ways. The computing platform is scalable, such that the number, resolution, and sensitivity of the cameras can be leveraged to improve image resolution and field of view. Miniaturization efforts can be pursued to shrink the package down for better mobility. Power savings studies can be performed to enable unattended, remote sensing packages. Image compression and transmission technologies can be incorporated to enable an improved telepresence experience

    Stereoscopic wide field of view imaging system

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    A stereoscopic imaging system incorporates a plurality of imaging devices or cameras to generate a high resolution, wide field of view image database from which images can be combined in real time to provide wide field of view or panoramic or omni-directional still or video images

    A MIDI sequencer that widens access to the compositional possibilities of novel tunings

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    We present a new Dynamic Tonality MIDI sequencer, Hex, that aims to make sequencing music in and across a large variety of novel tunings as straightforward as sequencing in twelve-tone equal temperament. It replaces the piano roll used in conventional MIDI sequencers with a two-dimensional lattice roll in order to enable the intuitive visualization and dynamic manipulation of tuning. In conventional piano roll sequencers, a piano keyboard is displayed on the left side of the window, and white and black note lanes extend horizontally to the right, into which a user can draw a sequence of notes. Similarly, in Hex, a button lattice is displayed in its own pane on the left side of the window, and horizontal lines are drawn from the center of each note to the right. These lines function as generalized note lanes, just like in piano roll sequencers, but with the added benefit that each note lane's height is always proportional to its pitch, even if the user changes the tuning. The presence of the button lattice on the left side of the window illustrates exactly which buttons a performer would play in order to replicate the sequence when playing a physical button lattice instrument

    Spectral tools for Dynamic Tonality and audio morphing

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    The analysis-resynthesis method used by the spectral toolbox allows the independent control of both frequency and amplitude for every partial in a given sound. The spectral toolbox begins by separating the 'signal' from the 'noise' which allows the peaks in the spectrum to be treated differently from the wide-band components. The spectral mapping technology is used to map the input to a fixed destination spectrum G like the SpT.Ntet routine maps all partials of the input sound to scale steps of the N-tone equal tempered scale that can be used to create sounds that are particularly appropriate for use in a given N-TET scale. Spectral morphing generates sound that moves smoothly between a source spectrum F and a destination spectrum G over a specified time t. A Dynamic Tonality synthesizer like Trans-FormSynth has a small number of parameters that enable many musically useful, and relatively, unexplored features like the continuous parameters α,β and γ move the tuning between a number of equal temperaments, non-equal temperaments and circulating temperaments

    Carbon-Carbon Cross Coupling Reactions in Ionic Liquids Catalysed by Palladium Metal Nanoparticles

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    A brief summary of selected pioneering and mechanistic contributions in the field of carbon-carbon cross-coupling reactions with palladium nanoparticles (Pd-NPs) in ionic liquids (ILs) is presented. Five exemplary model systems using the Pd-NPs/ILs approach are presented: Heck, Suzuki, Stille, Sonogashira and Ullmann reactions which all have in common the use of ionic liquids as reaction media and the use of palladium nanoparticles as reservoir for the catalytically active palladium species
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