His death was announced in a Twitter post by his son
"Hmm ... Sheer Heart Attack eh ? Well, I think I always worried a little bit about that album title"
A great loss for Greek music
We will, we will rock a small asteroid - for science!
UFO: "Thank you to everyone for your very kind and supportive messages"
King, who grew up in Southern California, co-wrote "Sweet Home Alabama"
He would perform with the band until the early 2000s, when he was slowed by a stroke
The group confirmed Clarke's death on Facebook