Katy Perry lights up the singles rankings and newbie Lorde announces her arrival on the charts this week. Here's what else you're downloading.

Fireworks For Katy
"Roar" sold more than 557,000 downloads in its first week of release, claiming the top spot on Billboard's Digital Songs chart. Katy — who's set to close Sunday nights MTV VMAs — logged huge first-week numbers that are not only the best of 2013, but of her impressive career, too: "Roar" surpassed "Firework" (which sold 509,000 copies in December 2010) to give Perry her biggest digital-song sales week ever.

And when you consider her recent record-setting run on the singles chart, well, that fact is even more impressive.

Applause for Gaga
Lady Gaga takes the third spot with her brand-new single "Applause" . Mother Monster, who's set to open the 2013 Video Music Awards when the show goes live at 9 p.m. ET, moved 218,000 downloads to open at #3.

Lorde Begins Her First Top 10 Reign
While the remainder of the Digital Songs chart remains relatively unchanged from last week — Robin Thicke's "Blurred Lines" is at #2, Jay Z's "Holy Grail" is #4, Miley's "We Can't Stop" sits at #6, etc. — there is one new addition who's raising eyebrows: 16-year-old alt-pop sensation Lorde, who crashes the Top 10 with her smash "Royals." The song, which also sits atop Billboard's Alternative chart, sold 107,000 downloads to land at #10. (It's her first Top 10 hit in the States.)

Elsewhere on the Digital Songs chart, Luke Bryan's "That's My Kind of Night" debuts at #5, selling 164,000 downloads, Avicii's "Wake Me Up!" is in at #7 (138,000 downloads sold), and Imagine Dragon's "Radioactive" slips from #4 to #8 (121,00 downloads sold, a 9-percent decrease from last week). Lana Del Rey and Cedric Gervais' "Summertime Sadness" holds steady at #9, selling 117,000 downloads.

Luke Bryan Is Country Strong
On the albums chart, it was Luke Bryan by a country mile. His Crash My Party debuts at #1 with sales of more than 527,000 copies, according to Nielsen SoundScan. It's the third-largest sales week of 2013, trailing only Justin Timberlake's The 20/20 Experience (968,000 copies) and Jay Z's Magna Carta ... Holy Grail (slightly over 528,000). It's also the largest sales week for an album by a male county artist since Tim McGraw's Live Like You Were Dying sold 766,000 copies in 2004.

Way back at #2 is K. Michelle's Rebellious Soul, which sold nearly 72,000 copies, followed by the 47th installment of the ubiquitous Now series at #3, with sales of nearly 52,000 copies, Robin Thicke's Blurred Lines (#4, more than 48,000 copies sold) and last week's chart champs, the Civil Wars, whose self-titled album sold 39,000 copies in its second week.

The rest of the Top 10 is rounded out by Jay's Magna Carta at #6 (more than 37,000 copies sold), the Teen Beach soundtrack at #7 (33,000 copies), Florida Georgia Line's Here's To The Good Times at #8 (31,000 copies), Imagine Dragons' Night Visions at #9 (27,000 copies) and Five Finger Death Punch's Wrong Side of Heaven and the Righteous Side of Hell, Volume 1 at #10 (22,000 copies).