Question: When was the vocalist that took over Bruce Dickinson's position as the lead vocalist for Iron Maiden born? 

full_context: Document 1: Paul Day (musician): Paul Mario Day (born 19 April 1956, Whitechapel, East London) is a British singer who is well-known as the original lead vocalist of Iron Maiden from 1975 to 1976.
Document 2: Throne to the Wolves: Throne to the Wolves is the fourth album by the post-hardcore band From First to Last. This was the only album by From First to Last to be released on the record label Rise Records and is the first and only album the band made without guitarist and backup singer Travis Richter (who left the band in 2009, returning in 2013 as part of their reunion). It is also the band's only release with guitarist Blake Steiner and the band's last release before their hiatus in 2010, until the band's reunion in 2013 whereupon they announced the recording of a new album. No song of the album has become a single, but "Going Lohan", "Cashing Out" and "I'll Inoculate the World with the Virus of My Disillusionment" were released in 2009, before album release, via MySpace for free listening.
Document 3: The King of Metal: The King of Metal is the sixth studio album by English heavy metal vocalist Blaze Bayley, released in 2012. This is the first album that Blaze recorded where he considers himself a "Solo Artist", having parted ways with the Blaze Bayley band that recorded The Man Who Would Not Die and Promise and Terror.
Document 4: Ozzy Osbourne: John Michael "Ozzy" Osbourne (born 3 December 1948) is an English singer, songwriter, and actor. He rose to prominence in the early 1970s as the lead vocalist of the heavy metal band Black Sabbath. He was fired from Black Sabbath in 1979 and went on to have a successful solo career, releasing 11 studio albums, the first seven of which were all awarded multi-platinum certifications in the US. Osbourne has since reunited with Black Sabbath on several occasions, recording the album "13" in 2013. His longevity and success have earned him the informal title of "Godfather of Heavy Metal".
Document 5: Promise and Terror: Promise and Terror is the fifth studio album by English heavy metal band Blaze Bayley, released in 2010. It is the second studio album released by the band since they changed their name from Blaze. It is also the first Blaze Bayley album without a title track.
Document 6: Ian Gillan: Ian Gillan (born 19 August 1945) is an English singer and songwriter. He originally found commercial success as the lead singer and lyricist for Deep Purple.
Document 7: Blaze Bayley: Blaze Bayley (born Bayley Alexander Cooke, 29 May 1963) is an English singer, musician, songwriter, and lyricist. He was the lead singer of Wolfsbane from 1984 to 1994, and currently from 2010 following reunions in 2007 and 2009. Bayley was also the lead singer for Iron Maiden from 1994 to 1999. Since then, he has embarked on a solo career.
Document 8: Virtual XI World Tour: The Virtual XI Tour was a concert tour by the heavy metal band Iron Maiden from 22 April 1998 to 12 December 1998. As with their previous tour, several of the band's U.S. shows had to be cancelled after vocalist Blaze Bayley had issues with his voice, this time reportedly from an allergic reaction to pollen and dust while the group were in Nevada and Arizona. The band later made up the Los Angeles and San Diego dates. This would be Iron Maiden's last tour with Bayley as then former vocalist Bruce Dickinson would return to the group the following year.
Document 9: Alive in Poland: Alive in Poland is the fifth release and second live album by English heavy metal band Blaze Bayley, released in 2007. It features mostly the band's original material, though they also play some Iron Maiden and Wolfsbane covers, as lead singer Blaze Bayley used to be in both bands.
Document 10: Axl Rose: W. Axl Rose (born William Bruce Rose Jr.; raised as William Bruce Bailey; February 6, 1962) is an American singer, songwriter, record producer and musician. He is the lead vocalist of the hard rock band Guns N' Roses, and has also been the band's sole constant member since its inception in 1985. In addition to Guns N' Roses, he has been the lead singer of AC/DC since 2016. Due to his powerful and wide vocal range and energetic live performances, Rose has been named one of the greatest singers of all time by various media outlets, including "Rolling Stone" and "NME".
Document 11: Bruce Dickinson: Paul Bruce Dickinson (born 7 August 1958), known professionally as Bruce Dickinson, is an English singer, songwriter, musician, airline pilot, entrepreneur, author and broadcaster. He is the lead singer of the heavy metal band Iron Maiden and is renowned for his wide-ranging operatic vocal style and energetic stage presence.
Document 12: Wolfsbane (album): Wolfsbane was the 1994 third eponymous album from British heavy metal band Wolfsbane. Not long after the album's release, vocalist Blaze Bayley took over Bruce Dickinson's position as the lead vocalist for Iron Maiden. It would end up becoming Wolfsbane's final studio album before their 16-year breakup from 1994 to 2010.
Document 13: Bark at the Moon: Bark at the Moon is the third studio album by British heavy metal vocalist Ozzy Osbourne, originally released on 15 November 1983. The album features former Mickey Ratt and Rough Cutt guitarist Jake E. Lee, who replaced guitarist Randy Rhoads who had been killed a year earlier in a plane crash. The album peaked at number 19 on the "Billboard" album chart and within several weeks of release was certified Gold for over 500,000 sales in the United States. To date, it has sold over 3,000,000 copies in the US. In the UK, it was the third of four Osbourne albums to attain Silver certification (60,000 units sold) by the British Phonographic Industry, achieving this in January 1984. The album was remastered on CD in 1995 and again (with a different mix) in 2002. This is the first album to feature guitarist Jake E. Lee and the only studio album to feature drummer Tommy Aldridge.
Document 14: As Live as It Gets: As Live As It Gets is the third release and first live album by English heavy metal band Blaze Bayley, then known as Blaze, released in 2003. It features mostly the band's original material, though they also play some Iron Maiden and Wolfsbane covers, as lead singer Blaze Bayley used to be in both bands. The band also covers the Led Zeppelin track "Dazed and Confused", which appeared earlier as a studio track on the Led Zeppelin tribute album ""The Music Remains The Same"".
Document 15: Bruce Dickinson discography: Bruce Dickinson, a British heavy metal singer, has released six studio albums, two live albums, one compilations, ten singles, three video albums, fourteen music videos, and one box set. In 1979, after playing in local groups, Dickinson joined hard rock band Samson. He departed after two years to become Iron Maiden's lead vocalist. His debut with this band is considered a "masterpiece", which was followed with a series of top-ten releases. In 1989, while Iron Maiden were taking a year off, Dickinson and former Gillan guitarist, Janick Gers, composed a song for . His solo debut, "Tattooed Millionaire" (1990), was an effort that favoured a hard rock/pop metal approach, different from what fans assumed would be an aggressive, Iron Maiden-like album. Four songs—the title track, "Dive! Dive! Dive!", "Born in '58", and a cover version of David Bowie's "All the Young Dudes"—were released as singles. Dickinson returned to Iron Maiden, accompanied by Gers as the new guitarist, and the project went on hiatus. "Dive! Dive! Live!" was a live video recorded from a concert in Los Angeles, California, in August 1990, and released in July 1991.
ground_truth: 29 May 1963