Lydia, born Lydia Rodriguez Fernandez, operates as a platinum-selling Spanish pop vocalist, composer, and lead singer for Presuntos Implicados. Professional music engagements began for her while she remained barely a teenager, resulting in the appearance of her self-titled debut album on WEA Latina once she turned 16. She paid tribute to her fellow Spaniard and key influence Alejandro Sanz by dedicating the single "El Tacto de Su Piel" to him, after which the record achieved platinum status and established her as an immediate sensation. Five singles ultimately emerged from that project.
Her next album, Cien Veces al Día, reached stores in 1998. The title track functioned as the opening single among four and propelled the set to gold certification. She delivered a performance of "Cien Veces al Dia" at the Eurovision contest the following year, which prompted a special-edition reissue of the album.
In subsequent years she maintained a presence on television, toured only sporadically, and continued issuing singles. One standout effort, her cover of the Beatles' "Across the Universe," served as the lead single for her last solo album, Si No Me Pides la Vida, released in 2002. The title track appeared as a duet with Nacho Campillo. That same year she contributed vocals to the Spanish metal band Mägo de Oz during the recording of their rock opera Jesús de Chamberí.
In 2006 she stepped in temporarily with longtime associates Presuntos Implicados to cover the vacancy created when vocalist Sole Giménez departed after twenty years. Although her schedule in 2007 centered on a role in the touring production of Jesus Christ Superstar, she still rehearsed with Presuntos Implicados from time to time and assumed the position of permanent lead vocalist in 2008.