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Foreground subtraction in global redshifted 21 cm measurements is limited by frequencydependent (chromatic) structure in antenna beam patterns. Chromatic beams couple angular structures in Galactic foreground emission to spectral structures that may not be removed by smooth functional forms. We report results for simulations based on two dipole antennas used by the Experiment to Detect the Global EoR Signature (EDGES). The residual levels in simulated foreground-subtracted spectra are found to differ substantially between the two antennas, suggesting that antenna design must be carefully considered. Residuals are also highly dependent on the right ascension and declination of the antenna pointing, with rms values differing by as much as a factor of 20 across pointings. For EDGES and other groundbased experiments with zenith pointing antennas, right ascension and declination correspond directly to the local sidereal time and the latitude of the deployment site, hence chromatic beam effects should be taken into account when selecting sites. We introduce the 'blade' dipole antenna and show, via simulations, that it has better chromatic performance than the 'fourpoint' antenna previously used for EDGES. The blade antenna yields 1-5 mK residuals across the entire sky after a 5-term polynomial is removed from simulated spectra, whereas the fourpoint antenna typically requires a 6-term polynomial for comparable residuals. For both antennas, the signal-to-noise ratio of recovered 21 cm input signals peaks for a 5-term polynomial foreground fit given realistic thermal noise levels. [ABSTRACT FROM AUTHOR]

The audio channel in computing interactions has been the focus of a variety of research interest in recent years. This paper examines one form of audio interface, earcons, in the context of information technology (IT) exception messages. Users of IT commonly encounter exception messages during their interactions with application programs. Exception messages often are accompanied by earcons which are aural messages of a musical nature used in the human–computer interface to provide information and feedback. Utilizing the notions of musical dissonance/consonance and pitch earcons were designed that vary as to their degree of aural disagreeableness and pitch. It is hypothesized that dissonant earcons (possessing aural disagreeableness) and low pitch earcons would be perceived as communicating a higher degree of hazard associated with an underlying computing problem signaled by an exception message. Results indicate support for the hypotheses. The implications are that it may be possible to increase the degree of hazard matching in IT environments by designing earcons to communicate different levels of perceived severity of an underlying computer problem. [ABSTRACT FROM AUTHOR]

The article discusses research on the disagreement between Arnold Schoenberg, an Austrian composer, and Heinrich Schenker, a music theorist, on the tasks of music theory in the 1910s and 1920s. It cites the conflicting views on of Schoenberg and Schenker on issues such as consonance and dissonance, the conditions for musical coherence, and the proper interpretation of the history of Western music. Schoenberg asserted that music theory was incomplete while Schenker insisted that music theory was complete. An overview of their works is offered.

The voice-leading rule of music theory that forbids consecutive perfect consonances of the same size between a pair of voices became firmly entrenched in the 14th century when counterpoint treatises began to replace those describing the older practices of organum and discant. A similar yet far more unusual rule discouraging consecutive imperfect consonances of the same size and quality appeared in the middle of the 16th century in the writings of a small group of music theorists that included two of the most significant of the period, Nicola Vicentino (1555) and Gioseffo Zarlino (1558). Others mentioning the rule about the same time include Jerome Cardan (c.1546) and Juan Bermudo (1555). Although Vicentino and Zarlino attempted to justify the new rule, their arguments appear strained and lack widespread substantiation in contemporaneous compositional practice. The present study examines their theoretical underpinnings for the rule, agrees with Karol Berger’s suggestion that the rule was taught by composer Adrian Willaert, and supports this hypothesis through analysis of Willaert’s madrigals. In Willaert’s magnum opus, Musica nova, written by early in the 1540s yet not officially published until 1559, parallel imperfect consonances are not avoided in general, but the false relation produced by consecutive major 3rds over a whole-step in the bass sometimes is used for expressive purposes. The fact that Willaert follows the rule less closely in his earlier madrigals than in his mature ones also suggests that it may have been of his own devising rather than being something he himself was taught. [ABSTRACT FROM PUBLISHER]