[en] Analysis of 221 velocities of b Persei covering the interval 1910--1975 reveals both 1.527364 day and 701 day periodic variations, implying that this single-lined system is actually triple. Systematic differences between Balmer and metallic line velocities plus the line profiles themselves suggest that unresolved blends do occur in the Balmer lilnes due to a weak contribution of secondary and/or tertiary light. We investigate possible parameters for the component stars. It appears likely that b Persei closely resembles Algol in spectral types and masses of the components, as well as in orbital parameters