Instruct: Classify Amazon reviews into positive or negative sentiment
Query: The best book out there

This is probably the best book on Spectral Analysis. A undergrad level probability / statistics is all that is required for reading through the book. The book develops the fundamentals of Spectral Analysis clearly and thoroughly and takes the reader through the various methods of spectral estimation. Parametric and Non-parametric methods are discussed and there are a variety of simulations that the reader can do in Matlab. The Matlab code is also provided in the website for the book. After going through the book, the reader would have enough knowledge in the field of spectral analysis to make her prepared for advanced reading / research in the subject. Also note that the book does not require any in-depth knowledge of Digital Signal Processing so it can be read by people in other areas who might need a knowledge of spectral analysis.