  We consider a magnetic Laplacian on a compact manifold, with a constant
non-degenerate magnetic field. In the large field limit, it is known that the
eigenvalues are grouped in clusters, the corresponding sums of eigenspaces
being called the Landau levels. The first level has been studied in-depth as a
natural generalization of the Kaehler quantization. The current paper is
devoted to the higher levels: we compute their dimensions as Riemann-Roch
numbers, study the associated Toeplitz algebras and prove that each level is
isomorphic with a quantization twisted by a convenient auxiliary bundle.
