Reverberation is an important factor of the acoustics in a room. It influences the acoustic perception of the listener and the performer. Each concert venue has its specific acoustic properties. Numerous studies regarding these properties have been conducted, mostly in real world or fully synthesized environments. However, both acoustic quality and perception in concert spaces are still not satisfactorily explained. The present thesis contributes new findings in the field of reverberation (late energy) for concert spaces. Previous concepts are further refined and novel approaches suggested. Several experiments are conducted in semi-virtual acoustics, namely real rooms whose existing acoustics is altered by means of an electronic reverberation system with loudspeakers. Thus, the possibility of changing the acoustic situation at the push of a button is offered, while the listeners’ visual and tactile perception remains the one from the real world environment. A lecture hall and a medium-sized concert hall equipped with enhancement systems are the test environments. Three aspects of reverberation are studied using this technique among others: reverberation level, spatial distribution of reverberation and the connection between signal dynamics and acoustics. The related perceptual attributes reverberance, listener envelopment and perception of dynamics are investigated by means of listening experiments. Following a qualitative investigation on enhancement systems, it is observed that reverberance depends highly on reverberation level. The method of only assessing decay time is not suffcient. An energy parameter such as strength must be included to predict reverberance. A loudness-based reverberation analysis is further explored and found to perform well in principle, however the three loudness models investigated differ noticeably. The direction of late reverberation in concert halls and the influence on the feeling of envelopment is further specified. Several tests show that the current measure neglects late reverberation from behind and above which contribute to listener envelopment. Lastly, the connection between signal envelope or dynamics and room acoustics is investigated, specifically regarding reverberation. Studies are conducted using, for example, a constant virtual orchestra source or a large pool of audio recordings from concert halls and opera houses. It is observed that reverberation alters the signal dynamic considerably, which is vital both in the context of acoustics and performance practice.

The acoustic and auditory properties of individual musical instruments have been extensively studied over recent decades, however, their sonic interplay within a musical ensemble remains under-explored. Given their considerable importance across various fields, aspects of ensemble sound, such as blending of instruments, perceptual relevance of directivity of instruments, and the role of room acoustics, demand comprehensive evaluations and an interdisciplinary approach. This study aims to improve the perceptually motivated acoustic representation of instruments in joint performance in both real and virtual acoustic domains, by exploring different stages of these aspects in musically realistic contexts. An explorative listening test with live string ensemble performance suggested that the characteristics of the acoustic environment considerably influence the blending of violins playing in unison. Combining methods of Machine Learning and Music Information Retrieval, a computational modelling approach is proposed to classify sound samples from an ensemble recording according to perceived blending. Proving this classification to be effective for monophonically rendered sound samples of two violins from in-situ environments, without requiring the individual source recordings marks a first step towards comprehensive blending modelling. Furthermore, the applicability of close-microphone recordings for auralization of a perceptually convincing ensemble sound was successfully demonstrated. Advancing previous research in directivity perception, it could be demonstrated that the room acoustics have a greater impact on the orientation perception of sources than their directivity. By involving instruments with distinct radiation directivities in a variety of acoustic environments, the major acoustical parameters influencing the orientation perception have been explored. Examining musical instruments with their inherent dynamic directivity against loudspeakers in in-situ conditions showed that their distinction becomes obscured under specific acoustic conditions. These findings led to a pilot study on the perceptual relevance of high-order directivity modelling of individual sources forming an ensemble. Results indicate, that even with an increasing number of sources, their detailed directivity characteristics remain pivotal for auralizing ensemble performance. The role of room acoustics in shaping the overall blending is shown to be dependent on the source-level blending. A computational model for predicting overall perceived blending in musical performance using source-level blending ratings and room acoustical parameters was suggested and validated. Analysis of its feature importance revealed that the room acoustic contribution to the overall blending impression is nearly as significant as the blending between instruments at the source level. By emphasizing and detailing relations between musical blending, directivity perception, and auralization aspects, this thesis contributes to the advancement of ensemble sound research and offers insights pertinent to music performance and perception research, virtual acoustics, and related fields.

This transcription of the "Twelve Fantasias for Viola da Gamba solo" for marimba is a project of the percussion-department at the Hochschule für Musik Detmold. The aim of this edition is, while staying as close as possible to the musical source, to offer some explanations and suggestions for performance practice on marimba.