Music chart to include streaming
Today's official singles chart will see o nline streaming from services such as Spotify and Deezer included for the first time.
The move to include streamed songs alongside downloads and physical sales follows a massive surge of interest in audio streams over the last 12 months, the Official Charts Company said.
Music fans have gone from streaming 100 million tracks a week at the beginning of last year to 200 million a week in January, while this has risen to between 250 and 260 million in the past month.
Listeners will need to have streamed a song for a minimum of 30 seconds for it to count, with 100 streams of a song counting as one sale.
Earlier this week the company said US singer Ariana Grande was way out in front to top the singles chart with Problem featuring Iggy Azalea selling more than double her nearest rival Ella Henderson.
By Tuesday Grande's song had clocked up around 55,000 sales - with 1% of those from streaming, while Henderson's track Ghost had 21,000 sales, 8% of which were from streaming.
George Ezra's Budapest was on course to rise to number three following his performance at last weekend's Glastonbury festival.
Meanwhile Ed Sheeran's Sing - expected to be number four - was predicted to be the most streamed track of the week with 13% of his sales accounted for through online listening, also possibly given a boost by his appearance at Glastonbury .
Other acts to have benefited from performing at the festival include country star Dolly Parton whose 1973 single Jolene is on course to make the top 40.