Warner Music act Gnarls Barkley's "Crazy" yesterday (April 2) made chart history by topping the Official U.K. Singles Chart solely on download sales.

Warner Music act Gnarls Barkley's "Crazy" yesterday (April 2) made chart history by topping the Official U.K. Singles Chart solely on download sales.

Charts compiler the Official U.K. Charts Company recently tweaked its criteria to allow download sales into the chart computation one week before a physical CD equivalent is released.

On the back of solid airplay of the track and broad support from the British media, Warner Bros Records U.K. made the digital version of the "Crazy" available to download three weeks ahead of its physical release at retail.

The CD format of "Crazy" will street on April 3, while 7" and 12" vinyl versions will hit the racks a week later.

In a statement, Korda Marshall, managing director of Warner Bros. Records U.K., described the move as "a milestone for us, for the industry and for music fans."

London-based OCC began publishing its combined singles chart in April 2005.

A spokesman for British-market leading music retailer HMV said the development illustrates that legal downloads have "truly arrived" but suggested that the digital format is some way from displacing the physical format.

"I doubt this will be a regular occurrence just yet and it doesn't mean the end of physical singles for the forseeable future,” noted the HMV executive. “Demand for CD singles and, particularly 7/12" vinyl remains and record companies are obliged to release these formats under current chart rules, but you'd have to say that the writing is on the wall."

The soul-tinged single is the first track from the act's forthcoming album "St. Elsewhere," which bows April 24. The digital format of "St Elsewhere" follows on May 1.

The pairing, a collaboration between Goodie Mob co-founder Cee Lo and artist-producer Danger Mouse, is booked for performances at the Coachella and Lollapalooza festivals in the United States, and a string of U.K. dates this summer.