This paper is a short review of magnetic neutron scattering experiment
s on La2-x(Sr, Ba)xCuO4. Special emphasis is given to measurements of
the spin waves using hot-source triple-axis and spallation-source time
-of-flight spectroscopies, magnetic fluctuations near the metal-insula
tor transition, Fermi surface effects and the dramatic impact of super
conductivity on the magnetic response function.