On 17th Nov broadcasting of 'Strong Heart', Jessica said:" sometime when comes to group singing portion of the song, i wouldn't sings.
Then Jessica added:" When Girls' Generation on stage, mostly the song would divided to group singing and solo portion; Taeyeon and me have to sing the climax chorus part on most of the song, despite bad condition of our voices".
"And this is a secret, sometimes i don't sing along with." the guests around her were surprised.
"When comes to my part of singing, it just can't help when my voice condition is bad; when comes to the part of group singing, i didn't sings sometime, really sorry to Taeyeon uunie". Hence, i would like to use this opportunity say sorry to Taeyeon.
On that day' Strong Heart', Jessica has revealed her 3 mistakes on performance stage.
"During 'Tell me your wish' performance, when we performing 'hacky sack dance', i have lost my high heel shoe". "Next, during 'Gee' performance, the strong fireworks effect are shocking me and my weird high-pitch voice just exploded". "Last one is during 'Way to go' performance, the song has jammed and just happen we  sync-lips on that day, the same dance need to repeated a few times". Every guests were burst into laughter after hearing Jessica.

Jessica(SNSD)'s Aegyo @ Strong Heart

Jessica(SNSD)'s Secret & Mistakes

source:snsdchina
Nicholas@NOW Is Girls Generation