Q: Passage: Originally considered for Gladys Knight & the Pips and later for Diana Ross, as "I Wanna Be Free", "I Want You Back" explores the theme of a lover who decides that he was too hasty in dropping his partner. An unusual aspect about "I Want You Back" was that its main lead vocal was performed by a tween, Michael Jackson.

Question: Based on this passage, who was the lead singer in i want you back? Let's give stream of consciousness first:
The relevant information is: An unusual aspect about "I Want You Back" was that its main lead vocal was performed by a tween, Michael Jackson. Therefore, the final answer is Michael Jackson.