Weeeewww.. Seriously THE hardest song to mix ever! It has the most background vocals. One part even had all, solo, bgv1, bgv2, bgv3 all at the same time O.o At first I wasn't confident mixing this, because it is that hard. And I eventually had to edit everyone's "echo echo" syllable by syllable so it's all aligned and neat.. So I'm happy to say, it did turn out nice in the end. Right? Right?? Don't you all think so??? heheheh.. The vocalists are great~ It's added to my favorite collab list, along with all the other collabs XD
 

Ari (Tae Yeon): I seriously love your voice as Tae Yeon! It's very powerful and has the same depth as she does. You also hit the high notes very well! And the laugh is perfect~ hehee..
Zoe (Jessica): High five harmony sister, great teamwork again! Keke.. Our harmonies sound so great together, lol. Your voice is really very sweet as Jessica here. I like how you switched to the low notes during the bridge though, it gave it a nice contrast from the other two :)
Melody (Sunny): Sunny is my bias in SNSD~ lol, I seriously don't know what to comment for myself XD You guys comment for me instead..? :3
Rai (Tiffany): See? Our Ba~a~a~a blend so nicely together~ Your voice is softer than usual though, I think? I'd love if it had more power, but it still sounds nice to the overall song anyway, so no problem here~
Zee (Hyo Yeon): Thank you for filling the empty spot at the very last minute and recording your part so fast! You brought the swag to the song during the bridge, but the chorus and your laugh was very sweet~ Hehehe.. The singing itself needs to be higher at some point. :p Hehe..
Kimmi (Yuri): Kimmi, I'm proud of you for doing this! Even though you said you'll sing Yuri's part in Tiffany's way, I can actually sense a similarity to Yuri! It's not overly flirty like hers, but it still has the sweetness and playfulness to it! I love it! During the bridge, the higher notes could be slightly higher though :p
Zelfon (Soo Young): Your part was very powerful and slightly sweet at the same time. It's a nice addition to this cutesy song. I love how during the bridge, your brought your swag back! Hahaha.. Good job Zelfon!
Hae In (YoonA): Your voice fits Yoona's part very well, especially right after Ari's deep voice. Your sweet and high voice made a great contrast. It is... (you know I'm gonna say it) CUTE~
Mimi (Seo Hyun): I'm also proud of you for doing this, and even volunteering to do the opening line! Seo Hyun's final line was kinda too high and you sounded a little forced, but the vibrato totally made up for it! LOL.. Love all the background vocals you did too! I knew your voice would be perfect for it~ <3

Lyrics distribution here.. Get ready for some craziness~