Artie (Kevin McHale) and Mercedes ( Amber Riley )
Sam sings Baby in the episode "Comeback".
Entitled "End Credits" (Made Famous by Glee Cast)
Laryngitis!
Idina Menzel or Shelby the Vocal Adrenaline's (competitive glee club) coach
No, everyone sings the same tune.
The whole glee club sings Push It in season 1 episode 2, Showmance.
Toby Keith sings the song Red Solo Cup.
If you mean ridin' solo it's buy Jason Derulo If it's called running solo idk who sings it
its not lean on you its lean on me and its Bill Withers
i am not sure
Valerie by The Zutons
Iyaz
The song Artie sings is Dancing With Myself
Sam sings Baby in the episode "Comeback".
Gwyneth Paltrow
Entitled "End Credits" (Made Famous by Glee Cast)
Bill Withers