In the Pyrenees, alpine accentors bred in polygynandrous groups of up to four males and four females. Complex songs were produced by females as well as males. Females sang only during their fertile period, and they sang at a greater rate when alone than when they were accompanied by one or more mateguarding males. Female songs elicited approaches from males, but not from other females, and females often solicited copulations as soon as the male arrived. Playbacks showed that males respond differently to, and hence distinguish between, male and female songs. This study provides the first evidence that female song in birds attracts males and we suggest that it has evolved in alpine accentors because both sexes compete intensively for mates in the polygynandrous groups. Female song may advertise quality as well as receptivity for mating because older females, which laid larger clutches, sang more complex songs. We show that female song not only attracts mates but may also provide females with a mechanism for sharing mating access among several males, so females obtain maximum paternal care for their offspring.