https://www.cnet.com/news/engineer-al-schmitt-explains-how-he-won-20-grammys/

Right away you could hear it in his voice, how much he loves his job. He's still working on getting better sound six decades into his career. He credits his success by giving musicians the sound they want. He always listened to what they want, and then tried to give it to them when he recorded or produced rock, pop, jazz, movie scores and classical music albums.

The best part of Al Schmitt's talk was recalling how that, early in his career he had wound up recording Mercer Ellington's big band session due to a scheduling mix-up. He had no clue how to record so many musicians at once, so while they were setting up he frantically looked around the studio for notes and diagrams on big-band mike placement. Before the band played a note, he told Mercer's father Duke Ellington that he'd never done anything like it before, but the jazz legend didn't seem the least bit concerned. All went well.