We develop a theory of
L
p
L^p
spaces based on outer measures generated through coverings by distinguished sets. The theory includes as a special case the classical
L
p
L^p
theory on Euclidean spaces as well as some previously considered generalizations. The theory is a framework to describe aspects of singular integral theory, such as Carleson embedding theorems, paraproduct estimates, and
T
(
1
)
T(1)
theorems. It is particularly useful for generalizations of singular integral theory in time-frequency analysis, the latter originating in Carleson’s investigation of convergence of Fourier series. We formulate and prove a generalized Carleson embedding theorem and give a relatively short reduction of the most basic
L
p
L^p
estimates for the bilinear Hilbert transform to this new Carleson embedding theorem.