SANTA MONICA (CBS) — The world knew Michael Jackson as the King of Pop, but he had another talent that he kept private. It turns out Jackson was also an accomplished artist.

Only a few individuals knew that Jackson had a secret studio in an airport hangar in Santa Monica, where he came to create, not music, but art and lots of it.

“A lot of people call his work just sketches, but I think they’re great works of art from one of the World’s most talented men,” said the late artist’s friend Brett Livingstone Strong.

Jackson had been painting and sketching since he was a young boy. Strong, his long-time friend and mentor gave us a first-hand look at some of Jackson’s artwork.

“He did these drawings of the Wright brothers, he loved them,” Strong said as he walked us through the collection.

Jackson, who was self-taught, had favorite themes.

Keys, chairs, gates and the number 7 appear in many of his works. Seven had special meaning for Jackson — he was the seventh child in his family.

“Over the decades he started expressing his feelings about his love of life and the things that he loved in life,” Strong said adding that Jackson often retreated to his artwork during some of the most difficult times of his life.

“His work wasn’t published, it wasn’t exhibited, but it didn’t stop him from being an artist. He kept working on it,” he said.

Strong also told us that Jackson’s plan was to sell reproductions of his artwork to help children’s charities. Jackson also wanted to sell limited editions to build a Michael Jackson monument, designed in part, by Jackson himself for his fans to visit and even get married under.

“It wasn’t meant to be a monument whereby he thought he was going to be honored after his life,” Strong said.

The monument is still in the works, as well as securing a spot to place it.

All of Jackon’s works, more than 150 in total, will eventually go on display, but only when “the time is right.”