Research into instrumental music practice has a long history dating back to the 1940s. This book presents papers dating from 1995 to 2022 by Prof. Susan Hallam, a former professional musician and instrumental teacher who on becoming an academic continued her interest in instrumental music by researching the factors contributing to the development of high levels of expertise, including practice. The papers variously explore issues relating to the importance of practice in acquiring musical expertise as opposed to having inherited musical ability; how practicing strategies develop from beginner instrumentalists through to the professional level; the management of practice; and the high levels of motivation required to develop expert musical skills. They illustrate the use of a wide range of different research methods, qualitative and quantitative. The book concludes with examples of successful instrumental music teaching at the primary school level and creative instrumental music making in the secondary school classroom. It differs from existing books that focus on practical guidance on practicing, as it presents the academic research underpinning this guidance. As an expert musician and researcher in psychology and education, Susan Hallam brings a personal and academic perspective to the study of the development of expertise.