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YouTube streaming data is being included in the methodology used to make up the US singles chart for the first time.

The Billboard Hot 100 is put together using figures from physical sales, downloads, radio airplay, audio streaming and online radio streaming.

It means viral hit, the Harlem Shake from Baauer, is the new number one.

The track is only the 21st song since the chart's launch in 1958 to go straight in at the top spot.

Billboard, along with statistics company Nielsen SoundScan, says it will now incorporate all official videos on YouTube, including Vevo on YouTube and user-generated clips that use official audio.

Billboard and Nielsen launched an On-Demand Songs chart in America last year and added streaming data from leading on-demand subscription services such as Spotify, Muve Music, Rhapsody, Slacker, Rdio and Xbox Music.

The Official Charts Company launched the UK's first Official Streaming Chart last year.

The main singles chart continues to be based purely on sales, the vast majority of which are digital.

In the UK, the Harlem Shake went in at number three on Sunday behind I Could Be The One, by Avicii vs Nicky Romero and Thrift Shop from Macklemore and Ryan Lewis.