Gloria Estefan will break new ground in Spain on Sept. 15 when she gives a free concert in Madrid's 15,000 capacity open-air Las Ventas bullring, the world's biggest such venue.

Entry will be available only to customers of the Vodafone mobile network. To be in the running for two free tickets, Vodafone clients must send an SMS to the network.

It will be the first free concert in Spain in such a large venue, although there are occasional similar events in venues with capacities of up to 1,500.

The concert will be organized by Sony BMG Spain and U.K.-based Vodafone during a four-day visit to Spain by Estefan to promote her new album, "90 Millas," which has a worldwide release on Sept. 18.

In the U.S., the album is released through Sony BMG's new imprint, Burgundy. Spain is the only promo target on Estefan's trip to Europe, although she will also play a concert in Zurich, Switzerland, before returning to her home in Miami.

The initiative is backed by a marketing campaign on radio, in the written press, and through Vodafone, which is Spain's second biggest mobile phone operator after Spanish mobile phone company Moviestar, owned by Spain's telecoms multinational Telefonica.

The concert marks the latest initiative between a growing music market relationship between Sony BMG Spain and Vodafone España, which began when Sony BMG released Spain's first digital-only album by Spanish band Statuas d Sal.

"This is the first time we have arranged a free concert on this scale," says Sony BMG local product manager Rafael Madroñal. "In reality, it is a showcase more than a concert, as Gloria will sing only seven songs, some from the new album and a few of her greatest hits."

Madroñal says there is "no doubt" Estefan will fill Las Ventas. "She sold 1 million units in Spain of her previous big Spanish-language album, 'Mi Tierra'. Hopefully, this concert will be the first of more such joint events by Sony BMG and Vodafone."

Vodafone Spain marketing director Ignacio Román says, "We chose Gloria Estefan for this event as she is not only a world famous artist, but also has a strong affinity with the Spanish public due to the her Cuban roots. This is the first time in Spain that a free concert of this scale is being organized with a world famous star."

According to Sony BMG, Cuban-born Estefan has sold 70 million units worldwide of her 24 published albums. Her new set is a tribute to the past 50 years of Cuban music, which Estefan says she adores even though she left the country aged 1.

Album guests include Carlos Santana, José Feliciano, Andy García, and double bassist Israel López "Cachao", acknowledged as the original exponent of Cuban mambo music.