Robert Anthony Plant, CBE (born 20 August 1948) is an English singer and songwriter best known as the vocalist and lyricist of the iconic rock band Led Zeppelin. He has also had a successful solo career. In 2007, Plant released Raising Sand, an album produced by T-Bone Burnett with American bluegrass soprano Alison Krauss, which won the 2009 Grammy Award for Album of the Year at the 51st Grammy Awards. With a career spanning more than 40 years, Plant is regarded as one of the most significant singers in the history of rock music, and has influenced contemporaries and later singers such as Freddie Mercury and Axl Rose. In 2006, heavy metal magazine Hit Parader named Plant the "Greatest Metal Vocalist of All-Time". In 2009, Plant was voted "the greatest voice in rock" in a poll conducted by Planet Rock. In 2011, a Rolling Stone readers' pick placed Plant in first place of the magazine's "Best Lead Singers of All Time".