"You have to be unique and different to stand out."

Riggs' legacy shares other links to China. He taught Chinese-American singer-songwriter Wong Lee-hom and Coco Lee. And he mentored Chinese singer Uta, the 2012 winner of the singing competition TV show Rock The Web. The classically trained musician from Guangdong's provincial capital Guangzhou recently released her English-Mandarin album Original Painting.

"There is no difference in teaching students coming from different countries," Riggs believes.

"There are many music talents in China, but nobody knows about them. I want to have more students in China."

Riggs teaches Doudou over the Internet because of the distance from his Los Angeles base.

The Washington DC native got his first paid job at age 8 as a Washington National Cathedral Choir soprano before his voice changed to baritone. He later received music degrees from the Manhattan School of Music in New York and studied acting with Lee Strasberg and Sandy Meisner.

His choir experience inspired him to develop his own singing method.

"When boys grow up, their voices drop," he explains.

"Nobody taught me how to reach a high pitch then. So I created my own method. I tested it again and again. Then one day I found the trick, and I wanted to tell everyone."

He taught for 10 years in New York, including three years on Broadway and two years at the New York City Opera. His students joined him because Riggs could easily correct their flaws according to their specific situations.

He previously helped Natalie Cole prepare for her Grammy-winning album Unforgettable and took Michael Bolton's voice to operatic levels for his performance with the late Luciano Pavarotti.

Riggs says he misses Michael Jackson most of all his students. He accompanied and coached Jackson on his 1988 world tour, and they worked together for more than three decades.

"He sang while I played piano, and suddenly he moves," he recalls.

"He thinks about his singing and dancing at the same time. He had dedicated so much to what he was doing. He is a legend.

"Many people asked me who would be the next Michael Jackson in the world, and I say no one," he continues.

"I have seen 38 Michael Jackson would-bes, and only one young man can do the same thing as Michael did, such as the singing and moonwalking."

But that singer couldn't establish an identity, he says.

Riggs attributes his success to continuously working. He feels fortunate he's alive at 83 and can teach people to sing better and hone their individual styles. He also says the music world is changing, and everything in it happens so fast today.

He is disappointed so few vocalists base their careers on singing.

"Justin Bieber came to my class twice and Rihanna once," he recalls.

"In the pragmatic world of show business today, where time is money, the young stars cannot dedicate themselves to the vocal training. Also, they cannot achieve what Michael Jackson had done with 30 years of training," Riggs says.

"I know there are many reality shows in China, like anywhere in the world. The TV shows are more for producers to make money than for the talents to be remembered," he says.

"You win a singing contest, and you think you will last forever. But, in fact, you just last for two minutes. ."