Azarenka's shrieks put to music

In a silent stadium, the sound can linger in the air.

Azarenka's friend, the American rapper Redfoo, who has produced multiple hit singles, has recognized some musical potential in the shriek. He recorded it and has mixed the sound into a new song due to be released soon, she said Monday.

"It's my grunt. It's not my vocals," Azarenka said, clarifying that she was not recorded singing. "I don't take high-key or low-key there. It's just natural."

Center court at Melbourne Park got a 57-minute Azarenka concert on Monday as she beat Elena Vesnina 6-1, 6-1 in the fourth round and continued her confident run toward the defense of her title. Going into the quarterfinals, Azarenka has dropped only one set.

Known for his wild hair and even wilder music, Redfoo has been seen cheering from Azarenka's players' box and signing autographs during most of her matches. Azarenka was quoted as telling Australian media that Redfoo, the LMFAO frontman whose real name is Stefan Kendal Gordy (he's the son of Motown Records founder Berry Gordy), had to fly off to a gig in Malaysia but plans to come back later in the week.

As an insider to the music world, Azarenka gets to listen to tunes the public hasn't heard yet — like a remix by Redfoo's friend GoonRock that she called "Sweet Baby" and says is "really good."

"Sweet Baby" was piping into Azarenka's earbuds as she walked onto center court Monday, as she often does soaking in some last-minute musical inspiration before turning to tennis.

"If it's bad music, it's going to be a bad match," she said. "So I really choose it very carefully."

Music is a "very important" part of her pre-match preparation, Azarenka told a post-match news conference.

It helps "focus, pump you up, get your feet a little bit moving, kind of get excited," she said. "I kind of get in the zone.