The existence of massive stellar-mass black hole binaries has been confirmed by the recent LIGO detections of their inspiral and merger. An estimate of the number of longer-period binaries that are precursors to the merging systems can be inferred from the observed event-rate. The Laser Interferometer Space Antenna (LISA) is a space-based gravitational wave detector that will be sensitive to the low-frequency gravitational waves from this precursor population at distances of up to 20 Mpc. I will provide a brief introduction to gravitational wave astronomy and discuss how the long-period binary black hole population can be used to obtain an independent measurement of the distances to galaxies in the Virgo cluster.