Seeing a few comments regarding individuals who are considered the "best" with their particular instrument.
I have to add my tuppence worth.
Deep Purple (the most successful and I think the No 3 outfit) of Gillan, Blackmore, Lord, Paice and Glover must be considered as the single most "multi-talented" groups ever to have graced the earth. My analysis may be common knowledge with some and unknown to others, but it goes like this.
(Once again, many aspects of talent are a matter of taste, but there is also plain "raw ability").
Ian Gillan - If none of his DP work makes your grade (which much of it should) check his vocals on the "all star" British recording of JC Superstar. As an ex-professional vocalist, I know no other "rock' voice which can compare.
Ritchie Blackmore - Considered by, not only critics, but by his peers, as one of the most talented and versatile R & B/Rock/Blues guitarists of his time (and probably others).
Listen to the solo on "Place in Line" on the "Who Do We Think We Are" album. It contains every conceivable style of modern guitar picking I can imagine.
Ian Paice - What can you say about the man that the professionals went to lessons for?
John Lord - Classically trained and accomplished pianist before he even saw a Hammond.
Roger Glover - Alas, I don't know much about Roger. I can't say I have read or recall any accolades or complimentary accounts by his peers or critics, but to be in such company, he just had to be pretty good, I reckon.