The hip-hop rapper Biz Markie, known for his beatboxing prowess, turntable mastery and the 1989 classic 'Just a Friend', has died aged 57. Richard Shotwell / Invision / AP File
The hip-hop rapper Biz Markie, known for his beatboxing prowess, turntable mastery and the 1989 classic 'Just a Friend', has died aged 57. Richard Shotwell / Invision / AP File

US rapper Biz Markie dies aged 57: 'We're mourning a true son of Harlem tonight'