Katy Perry's 'Roar' Tracking to Move 450,000 Downloads in First Week

Lady Gaga/Twitter; Getty Images

Lady Gaga, Katy Perry

Meanwhile, sales forecast for Lady Gaga's "Applause" sees a change

Katy Perry's new song "Roar" is off to a roaring sales start, with industry forecasters suggesting it will move around 450,000 downloads by the end of the tracking week on Sunday (Aug. 18).

Meanwhile, fellow diva Lady Gaga is also off to a handsome launch with her new single "Applause." It's heading for a bow of perhaps 200,000 to 225,000 downloads.

"Roar" and "Applause" were released to digital retailers on Monday and Tuesday (Aug. 12 and 13), respectively. The songs preview new studio albums for each superstar: Perry's "Roar" leads her "Prism" set, due out Oct. 22. "Applause" is the first single from Gaga's "ArtPop," which arrives on Nov. 11.

On Monday, Aug. 12, there were early indications that both "Roar" and "Applause" could sell over 400,000 downloads. At the time, industry sources theorized that, considering both artists' stellar track history with digital song sales, a robust first-week for the two acts seemed likely.

However, once the songs went on sale, the forecast changed. Still, we have four more days left in the tracking week -- so anything can happen.

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Perry's sales start benefits slightly from how it will have a full seven days worth of sales in its debut. Most songs are released to retailers on Tuesday of each week, whereas "Roar" bowed on a Monday. "Roar" will get seven days of sales in its first week, as Nielsen SoundScan's tracking week runs from Monday through Sunday each week. (Yet, most new songs and albums are released to retailers every Tuesday.)

Gaga's last studio album, 2011's "Born This Way," was led by its title track, which debuted at No. 1 on the Digital Songs chart with 448,000 downloads after only three days on sale, according to Nielsen SoundScan. (It hit retail on an off-cycle Friday, instead of the usual Tuesday.) In its second chart week (and first full sales week), it moved 509,000 downloads.

Perry's last new album, 2010's "Teenage Dream," was ushered in by the single "California Gurls." It bowed at No. 1 on the Digital Songs chart with 294,000. Perry has sold more than 400,000 in two previous weeks: when "Firework" shifted 509,000 over the busy post-Christmas week of 2010, and when "Part of Me" debuted in 2012 (411,000).

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If both "Applause" and "Roar" debut with sales larger than 200,000, it will be the first time two songs have sold that many copies in their debut week since last October. On the Digital Songs chart dated Oct. 20 (reflecting the sales week ending Oct. 7), three new tunes arrived with sales exceeding 200,000: One Direction's "Live While We're Young" (341,000), Taylor Swift's "Red" (312,000) and Adele's "Skyfall" (261,000).

The final sales tally for both will be released on the morning of Wednesday, Aug. 21.