f(x)'s Amber expressed her thanks to Girls' Generation's Taeyeon on the February 24th airing of KBS Radio CoolFM's 'Jang Dong Min and Lady Jane's 2 O'Clock'.

As fans may know, Taeyeon featured in her SM Entertainment hoobae's solo debut track "Shake that Brass". Amber said on the show, "I thought a lot about who I should collaborate with. Suddenly, I thought of Taeyeon. She's a very good unni and sunbae. She took care of me and gave me a lot of advice."

Amber also discussed why she didn't work with her fellow f(x) members, "It would've been easy to collaborate with the f(x) members because I've been with them for 6 years. However, because it was a solo album, I wanted to challenge myself to something new."

In other news, the "Shake that Brass" MV hit a million views on the first day of its release. Have you seen it?