Roy Orbison, Luciano Pavoratti if only for Nessun Dorma (sp?), and Bing Crosby. Can you imagine Bing is a modern recording?
I can't really speak for Bing's recordings, since I never heard one on anything other than the car radio - but if they were anywhere near as good as Frank Sinatra's, well let's just say we have not come far from that level of quality with all of our modern technology. The best of the engineers of that era were g-o-o-o-o-o-d, and the recordings were absolutely outstanding by even the most contemporary standard. Digital schmigital - those guys
rocked!!!!Bing, by the way got his hands on
the first modern tape recorder in the USA, one of the ones that were brought back from Germany. He had connections! This machine was used to record his radio shows so they could be broadcast at the same time in the different time zones across the country. If I'm not mistaken, he showed up at Les Paul's place with one of these machines and said in effect, "Here, Les, play with this!"
These German machines were thought to be about 10 - 20 years ahead of our technology at the time (have you heard of wire recorders?) and led to the Ampex brand.
I imagine he would have been recorded by the best engineers in the States, and they were good. Have you ever heard any of the Elvis recordings before they slathered reverb all over them? Elvis hated the "echo" as he called it, but the originals are astonishing, as were Buddy Holly's and Roy Orbison's.