I was fortunate enough to get front row seats for their 1973 tour through Dallas, Texas; this, of course, included the classic Deep Purple line-up :

Ritchie Blackmore
Jon Lord
Ian Paice
Roger Glover
and the incomparable Ian Gillan

In the early 70s, they were one of many rock bands on the top of their game.
FIREBALL and MACHINE HEAD were monster albums...........good work.

RIP Jon Lord.