There are hundreds of rock songs produced in the 60's, that have him playing guitar in the studio. He even toured with the Beach Boys when one of them (I forget now), had a breakdown.
It's like when you watch Prince destroy 'While my guitar gently weeps'
Or when you catch Karen Carpenter on the drums
These people are invested to the teeth with their art and they share it with us in the form of memories that we can revisit. Their passing is a loss to us all.