Each period of orchestral history had its own ideal of sound, and it was not the creative musician alone but also the audience he wrote for who together determined the ideal of the time. The author points out the particular conditions from which the ideal grew and he marks the connections between ideals of different epochs, showing in what ways they were related and in what ways independent of each other. The composers themselves, their works, and the conductors too are involved in this presentation, but the aim is always to keep before the reader an understanding of how each type of orchestra belonged to and was justified by its own time. Mr. Bekker's scholarship and his original and provocative ideas make this analysis an extremely valuable contribution to musical literature.