This book contains five theses in analysis, by A C Gilbert, N Saito, W Schlag, T Tao and C M Thiele. It covers a broad spectrum of modern harmonic analysis, from Littlewood-Paley theory (wavelets) to subtle interactions of geometry and Fourier oscillations. The common theme of the theses involves intricate local Fourier (or multiscale) decompositions of functions and operators to account for cumulative properties involving size or structure.