Sunny "Now"

Tiffany "Only Me"

Jessica "One Year Later" (with Onew) "Cold Noodles" (with Park Myung-soo ) "Don't Cry"

Taeyeon Sunny "It's Love"

Taeyeon "Can You Hear"

Tiffany Jessica Heo Hyun "Bad Brother"

Tiffany Jessica Heo Hyun Taeyeon Sunny "Little White Boat"

Heo Hyun "Cha La Cha Cha" (with Joo Hyun Mi)

Tiffany and Taeyeon and many more, I don’t know much about it. You can go to Kugou Search and type in “tiffany Girls’ Generation” and there will be many