THIS issue of Empirical Musicology Review is a good example of the breadth and diversity of empirical music research, both in terms of disciplinary approaches as well as the stylistic variety of musical material covered. The article by Kopiez, Wolf, and Platz is a replication and extension of a performance research study following the classical experimental approach dominating psychological research. Using this experimental paradigm, the authors are able to show that instrumental solo performances from memory only achieve a small positive effect on audience appreciation compared to performances using a music stand on stage. White's paper also employs classical experimental paradigms in order to assess the cognitive question to what degree tonally stable notes and metrical accents are associated in listeners' perception. Overall, White finds evidence for a joint tonal-metric hierarchy, though the association between tonal and metrical emphasis does not seem to be fully symmetrical. The contribution by Zicari represents a systematic study of aria recordings by Adelina Patti form the early 20th century. Zicari is able to argue with empirical evidence that, while Patti makes use of expressive tempo to convey the dramatic meaning of the arias in line with established performance conventions from the 19th century, she is able to stay clear of abusing the composer's intentions with any exaggerated interpretative choices. The paper by Huisman, Gingras, Dhondt, and Leman also comes from the field of musical performance research and compares different learning trajectories and performances of the same complex piece of contemporary music as performed by different musicians learning from different graphical score editions of the same piece. Results link back to models from embodied music cognition when performers make use of embodied associations between images of the scores and motor actions. Finally, Duinker presents a corpus study of hip-hop recordings to assess whether the so-called 'golden age of hip-hop' (1986-1996) can be described by a distinctive sound, and to what degree this sound is a homogeneous phenomenon or characterized by change over time in individual sound parameters and production techniques.

These five target articles are complemented by six commentaries that offer alternative perspectives and additional interpretations on the empirical findings and inferences presented in the target papers. In all cases, reading the commentaries alongside the target papers will enable the reader to gain a wider perspective on the research questions tackled and will help to stimulate an active and productive reception of the research presented here. The book review by Harrison completes this issue and offers both a concise and easy-to-read summary, as well as a critical discussion of the contributions to an edited volume by Smith, Chew, and Assayag that covers a wide variety of aspects in mathematics and computation in music performance and composition.