The singer's official Diamond Jubilee track 'Sing' - which features the Commonwealth Band and the Military Wives - moves up to number one on the midweek singles tally.
Usher's new single 'Scream' lands at two, fun.'s 'We Are Young' is at three, while DJ Fresh and Dizzee Rascal are a new entry at four with 'The Power'.
Last week's number one 'Feel The Love' by Rudimental is down to five, Coldplay and Rihanna's 'Princess Of China' advances to seven and Nelly Furtado's 'Big Hoops' enters at 12.
Lady Antebellum's 'Need You Now' is up to 26 following Barlow and Cheryl Cole's rendition of the US country track during Monday's Jubilee concert.
Elsewhere, The Voice UK winner Leanne Mitchell is at 27 with 'Run To You', Aiden Grimshaw is at 30 with 'Is This Love' and Justin Bieber is at 33 with new album track 'All Around The World'.
Over on the album chart, Gary Barlow and the Commonwealth Band's record Sing remains at number one, while Ed Sheeran vaults 11 places up to number two with his debut +.
Paloma Faith's Fall To Grace slips a place to three, Coldplay's Mylo Xyloto is up to four and Rumer's Boys Don't Cry slides to five.
Alexandra Burke's second studio album Heartbreak On Hold is at 14, Kylie Minogue's The Best Of lands at 16 and The Voice UK runner-up Bo Bruce is at 19 with her 2010 EP Search The Night.
Watch the music video for 'Sing' by Gary Barlow and the Commonwealth Band featuring the Military Wives below: