A music score is a primary source because it provides direct evidence of the composer's intentions for the musical work.

A literature review serves all of these purposes. It helps researchers to identify areas where more research is needed, to understand the current state of knowledge on a topic, and to evaluate the quality of the existing research.

Experimental manipulation of musical variables is a quantitative research method because it involves the systematic manipulation of one or more variables to observe their effects on a musical outcome.

A hypothesis is a specific statement that predicts the outcome of a research study. A research question is a general question that guides the research process and helps to focus the research design.

Internal validity refers to the extent to which a study's results are accurate and reliable. External validity refers to the extent to which a study's results can be generalized to other populations or settings. Construct validity refers to the extent to which a study's measures accurately reflect the concepts they are intended to measure.

A research proposal serves all of these purposes. It provides a detailed overview of the research project, including the research question, methods, and expected outcomes. It also helps researchers to secure funding and obtain approval from an IRB.

All of these are important ethical considerations in music research. Researchers must obtain informed consent from participants, protect their confidentiality, and respect their privacy. They must also avoid plagiarism and copyright infringement, and protect the rights of researchers and institutions.

Peer review is a process in which experts in a particular field review and evaluate research studies before they are published. This process helps to ensure the quality and rigor of research publications.

All of these statements are true. Journal articles are typically shorter and more focused than book chapters, while book chapters are typically more comprehensive and in-depth. Journal articles are typically peer-reviewed, while book chapters are not.

A bibliography serves all of these purposes. It provides a list of sources that were used in the research project, gives credit to the authors of those sources, and helps readers find more information on the topic of the research project.