16:00The Official Chart on Radio 1 with Jack Saunders18/03/2012BBC Radio 1 Duration: 3 hours Sun 18th Mar 2012, 16:00 on BBC Radio 1 N. IrelandAlexandra Burke joins Reggie as he counts down the Top 40 to reveal the UK's new Official No 1 with the Top 10 videos streamed live online at bbc.co.uk/radio1.GenresMusicPop & ChartExperimental & NewEntertainmentBrandThe Official Chart on Radio 1 with Jack Saunders Source: BBC Online