"Wannabe" is an uptempo dance-pop and pop rap song that incorporates a mix of hip-hop and rap. The lyrics, which address the value of female friendship over the heterosexual bond, became an iconic symbol of female empowerment and the most emblematic song of the group's Girl Power philosophy. Despite receiving mixed reviews from music critics, the song won for Best British-Written Single at the 1997 Ivor Novello Awards and for Best Single at the 1997 BRIT Awards.
"Wannabe" was heavily promoted by the group. Its music video, directed by Jhoan Camitz, became a big success on the British cable network The Box, which sparked press interest in the group. Subsequently the song had intensive radio airplay across the United Kingdom, while the group performed it on television programmes and started doing interviews and photo shoots for teen magazines.
Released as the group's debut single in July 1996, "Wannabe" topped the UK Singles Chart for seven weeks and received a platinum certification by the British Phonographic Industry (BPI). In January 1997 it was released in the United States, topping the Billboard Hot 100 for four weeks. It was the group's only number-one single in that country.