I had dinner with late Joe Sok in HK in 2004, then visited him in Macau 2007 and last saw him 1 week before he left us in 2011. He taught me alot of CO things and also presented me with his Gu Hong CDs and I have to continue his work to spread and retain gu hong too. Also I did ask him whether it is necessary of a singer to learn 嗌声 and he commented NO as singers are NOT Cantonese Opera actors/actresses and the more we do the more we failed! He never did and I hear him very clear and crisp even he was already 80+ . He was always willing to share with those interested to know more. We missed his advices.