This yearbook photo was taken in 1957 and is from The Cate School in Carpinteria, California. It hardly indicates the signature look this rocker, born August 14, 1941, would go on to cultivate later in life. Nowadays, he is nearly as well-known for his bushy white mustache and hair as he is for work as a guitarist, singer and songwriter.

He has been a member of not one, not two, but three well-loved rock bands over the course of his illustrious career. He has also enjoyed time as a solo artist, but his most familiar work is that which he created as part of a trio.

What else is interesting about him? Well, he voiced himself on two episodes of ‘The Simpsons’ over the years. This rocker also donated his sperm in order to help one of his friends and peers raise a family. Think you know who it is? Find out here!