Katy Perry Crowns 'The Best Voice' In Pop: Who Is It?

Perry dubs Ariana Grande the 'best female in pop music,' and now, the two are headed down BFF lane.

Ariana Grande has a new #1 fan and she just so happens to be one of the biggest pop stars in the world.

During a recent interview with Sirius XM, Katy Perry couldn't help but gush over the 20-year-old up-and-coming singer.

"I love her. I think she has the best female vocal in pop music today," said Perry, who previewed bits of Prism Tuesday (October 15) morning. "She has literally the best voice, the best voice live. She kills it. She's so good."

Perry admits she sees the comparisons between Grande and Mariah Carey, but that she is "different." And prepping her for stardom, Perry went out of her way to lend some friendly advice.

"I got to hang out with her and listen to her record before it came out because I wanted to reach out to her and be like, 'Hey girl, you're just about to go through a whirlwind. Let me give you some tips if you ever need anything -- a hairstylist, makeup artist, whatever,' " Perry said. "And she's the sweetest girl and I just wish her the best."

Thank you so much @KatyPerry for being a true friend & an inspiration to me i love you everybody buy #PRISM

— Ariana Grande (@ArianaGrande) October 15, 2013

Grande tweeted Perry after her kind words, thanking her for "being a true friend & an inspiration." During "Live from MTV" in August, days before the 2013 MTV Video Music Awards, "The Way" singer told MTV News that the one person she was excited to see perform was Perry.

"I'm so excited to see Katy," Grande said. "I love her new single so much. 'Roar' is everything. It came out, and I did not stop playing it on repeat."

"Roar," along with "Dark Horse" and others, appears on Perry's October 22 album, which she described to SiriusXm:

"I think there are a lot of fun party songs of the record that don't have any anthemic message because I still like to do that stuff like 'Last Friday Night (T.G.I.F.).' I still like to have fun, obviously," Perry said. "But I think there's some really important songs on here."