With the help of Alicia Keys, Usher grabs his fourth No. 1 on Billboard's Hot 100 this year. Their duet, "My Boo," moves up one and into the top slot, ending Ciara's seven-week reign with "Goodies" fe

With the help of Alicia Keys, Usher grabs his fourth No. 1 on Billboard's Hot 100 this year. Their duet, "My Boo," moves up one and into the top slot, ending Ciara's seven-week reign with "Goodies" featuring Petey Pablo, which falls to No. 2.

Already in 2004, Usher has been on top of the Hot 100 with "Yeah!" featuring Lil' Jon and Ludacris, "Burn" and "Confessions Part II," all stemming from his latest album, "Confessions" (LaFace/Zomba). "My Boo" is available on the reissued version of "Confessions" that entered The Billboard 200 last week at No. 2.

As they settle into No. 1 together, the duo's biggest competition for the throne looks like Nelly's "Over and Over" featuring Tim McGraw, which is the chart's greatest airplay gainer. The cut lurches forward 10 positions to No. 8 on the Hot 100 while simultaneously earning Nelly his best placing on the Mainstream Top 40 airplay chart, where it breaches the top 10 in its third week to land at No. 7.

With an 11-7 move, Snoop Dogg enters the top 10 this week with "Drop It Like It's Hot" featuring Pharrell, while Kelly Clarkson grabs her third top 10 Hot 100 single with "Breakaway," which moves 12-10. The track from Disney's "The Princess Diaries 2: Royal Engagement" soundtrack joins Clarkson's previous top tier songs "A Moment Like This" and "Miss Independent."

As for the rest of the top 10, Destiny's Child's "Lose My Breath" jumps 4-3, Terror Squad's "Lean Back" falls 3-4, Maroon5's "She Will Be Loved" sits at No. 5 for a second week, Eminem's "Just Lose It" gains 7-6 and Akon's "Locked Up" featuring Styles P. drops 8-9.

Blake Shelton's "Some Beach" is the Hot 100's top debut at No. 65, while Ciara enters the chart with a second single, "1,2 Step" featuring Missy Elliott, at No. 74.

Also debuting this week are Trace Adkins' "Rough & Ready" (No. 77) and Body Head Bangerz' "I Smoke, I Drank" featuring YoungBloodz (No. 85). Re-entering the chart this week is New Edition's "Hot 2Nite" (No. 90) and R. Kelly's "U Saved Me" (No. 94).

Nitty's "Nasty Girl" is the Hot 100's fastest growing song at retail and takes a 96-92 jump on the tally. Cuts making substantial moves include Fabolous' "Breathe" (42-24), Chingy's "Balla Baby" (41-25), Ja Rule's "Wonderful" featuring R. Kelly & Ashanti (60-34), Terror Squad's "Take Me Home" (94-78) and Mario's "Let Me Love You" (97-80).

Green Day's "American Idiot" remains atop Billboard's Modern Rock Tracks for a sixth consecutive week while Velvet Revolver's "Fall to Pieces" is No. 1 on the Mainstream Rock Tracks list for a fourth.

George Strait is No. 1 on the Hot Country Singles & Tracks list with "I Hate Everything," as his MCA Nashville compilation "50 Number Ones" is tops The Billboard 200 and Top Country Albums charts for a second week in a row.