According to Wikipedia, Michael Jackson was born in August 1958 and joined The Jackson 5 in 1964. So, since there is no date listed as to the official creation of The Jackson 5, he was about 5.
Jackie, Tito and Jermaine formed the "Jackson Brothers" in 1964, they added Marlon and Michael in 1965 and became the "Jackson Five". Michael was 8 years old when he first performed with them.
About 20 years old
Michael Jackson was first signed to Motown Records as part of the Jackson Five in 1969. He was 11 years old at the time.
He was eight years old when Micheal Jackson started performing in the Jackson five.
Bad
Michael Jackson was 6 years old when he joined "The Jackson Brothers" in 1964. He played the Congas.
Jackie, Tito and Jermaine formed the "Jackson Brothers" in 1964, they added Marlon and Michael in 1965 and became the "Jackson Five". Michael was 8 years old when he first performed with them.
About 20 years old
he was five
Michael Jackson was actually 5 years old. He sang in front of his Kindergarten class.
He was five years old.
Michael Jackson was first signed to Motown Records as part of the Jackson Five in 1969. He was 11 years old at the time.
He was eight years old when Micheal Jackson started performing in the Jackson five.
Bad
Michael Jackson had been a performer since he was five years old, therefore he was a performer for nearly 45 years.
Michael Jackson has two sons actually. Michael Jackson's oldest son is 13 years old, his name is Prince Michael Joseph Jackson I. His second son is 8 years old, his name is Prince Michael Joseph Jackson II also known as Blanket.
Oh, dude, Michael Jackson started singing in the Jackson 5 when he was like, a wee little child. He joined the group in 1964 when he was just a tiny tot of 5 years old. So yeah, he basically popped out of the womb singing "ABC" and "I Want You Back."