As of 2017, what is the biggest-selling album in music history by a girl group?

'Spice' is the debut studio album by English girl group the Spice Girls. It was released on 19 September 1996 by Virgin Records. The album was recorded between 1995 and 1996 at Olympic Studios in Barnes, London, by producers Matt Rowe and Richard Stannard, and the production duo Absolute. The album is a pop record with an inclusion of styles such as dance, R&B and hip hop. It is considered to be the record that brought teen pop back, opening the doors for a wave of teen pop artists. Conceptually, the album centered on the idea of Girl Power, and during that time was compared to Beatlemania.

'Spice' was a huge worldwide commercial success. The album peaked at number one in more than 17 countries across the world, and was certified Multi-Platinum in 27 countries, Platinum in 14 countries and Gold in three countries, including 10-times Platinum in the UK and Canada by the British Phonographic Industry and the Canadian Recording Industry Association, 8 times Platinum in Europe by the International Federation of the Phonographic Industry, and seven-times Platinum in the US by Recording Industry Association of America. It became the world's top-selling album of 1997 selling 19 million copies in over a year. In total, the album sold 23 million copies worldwide, becoming the biggest-selling album in music history by a girl group and one of the most successful albums of all time