Black sabbath for chart lovers
The chart show - long a staple of Sunday evening listening - is moving to Friday after the music industry agreed a change in release dates for new albums and singles.
Radio 1's Greg James will present the new t op 40 run-down, which will be an hour shorter than the current show, from 4pm to 6pm on Fridays.
Station controller Ben Cooper said the move did not mean the chart was being "downgraded".
He said: "If anything this gives the chart a new lease of life, it gives it an exposure to a new audience on a Friday afternoon and it gives it a new presenter and it gives it a new format. It's going to have to be tighter and slicker."
UK singles currently come out on Sundays and albums a day later, but the IFPI - which represents the worldwide record industry - announced last month they were introducing Friday as a global release day from summer.
Mr Cooper said the new show would have to be "a little more choosy" about which tracks it played but pointed out the current three-hour long show does not play all 40 tracks. He said the top 20 would be played every week.
He said the Sunday night show, presented by Clara Amfo, attracts around 1.2 million listeners, while Greg James pulls in more than 5 million across the week.
James backed the move, saying: "The chart must feel like it's providing news, not just confirmation of something the listeners already knew."
The Sunday slot is expected to be filled with a new show co-produced with CBBC in a big to bring a younger audience to the station.
The charts, which have been played on Radio 1 on Sundays for decades, recently started including online streaming sales.