What singer born in London in 1988 joined The Voice as a new judge in 2015?
The Voice (Australia season 4):  On 13 January 2015, it was announced that Delta Goodrem would return to the panel, and new judges Jessie J and Benji Madden would join the series, replacing former judges Kylie Minogue and will.i.am. Jessie J: Jessica Ellen Cornish (born 27 March 1988), known professionally as Jessie J, is an English singer and songwriter.
i don't know