For a given nonnegative integer α, a matrix A n of size n is called α-Toeplitz if its entries obey the rule A n = [a r−αs ] n−1 r,s=0 . Analogously, a matrix A n again of size n is called α-circulant if A n = a (r−αs) mod n n−1 r,s=0 . Such kind of matrices arises in wavelet analysis, subdivision algorithms and more generally when dealing with multigrid/multilevel methods for structured matrices and approximations of boundary value problems. In this paper we study the singular values of α-circulants and we provide an asymptotic analysis of the distribution results for the singular values of α-Toeplitz sequences in the case where {a k } can be interpreted as the sequence of Fourier coefficients of an integrable function f over the domain (−π, π). Some generalizations to the block, multilevel case, amounting to choose f multivariate and matrix valued, are briefly considered.Theorem 2.1. Let B be an arbitrary (complex) m × n matrix. Then: (a) There exists a unitary m × m matrix U and a unitary n × n matrix V such that U * BV = Σ is an m × n "diagonal matrix" of the following form: Σ = D 0 0 0 , D := diag(σ 1 , . . . , σ r ), σ 1 ≥ σ 2 ≥ · · · ≥ σ r > 0.Here σ 1 , . . . , σ r are the nonvanishing singular values of B, and r is the rank of B.