This American artist made the Billboard top 25 and was a well known YouTuber and also for her participation in which NBC singing competition? 
Side A (EP): Side A is the second EP by American artist Christina Grimmie. Side A (EP):  The EP was released independently and debuted at number 25 on the "Billboard" Independent Albums chart in the US. Christina Grimmie: Christina Victoria Grimmie (March 12, 1994June 10, 2016) was an American singer, songwriter, musician, actress and YouTuber known for her participation in the NBC singing competition "The Voice" and for her covers of hit songs by contemporary pop musicians.
The Voice