Having attempted to create original material for a college-level sight singing class, I must admit that this book would have (and has since) saved me months of frustration. The music in this book is more than sufficient to create several sight-singing courses and I trust the folks who compiled it. There is a great range in both difficulty and complexity, and all meters, key signatures, and even "exotic" scales (their words) are included; the music progresses from single line to polyphonic; and rather than adhere to a rigid methodology, only short suggestions of how to approach the work are offered. There are more than enough examples for every type of student and I think this book would be a great supplement to other instrumentalists, as well, covering sight-reading skills that could also include comfort with different clefs, transposition, and melodic, harmonic, and contrapuntal figures that might be different than the standard repertoire for one's instrument.