I would say most famous players started on what they could afford, then switched to a particular brand as they became famous, which was the objective of marketing policies when a brand sponsored the performer. This occurred with James, Armstrong, Hirt, Severinsen. The only famous performer I have met who started and ended with a single trumpet was Alpert, who loved his Benge. If industry standard is defined by prevalence, then Bach is the standard by which all other horns are judged. In the '70s, I never encountered an advanced student or pro orchestral trumpeter who did not have a Bach. Back then, we had many brands, but none gave the performance and sound of the Bach brand. Fast forward 50 years, today we have many brands that compete head to toe with Bach. This is perhaps driven by competition: economics; and the desire of players to have a "unique" sound. We are now, arguably, in a golden era for trumpets, when we have a very extensive and confusing array of trumpets available, the majority of high quality. In 1970, the choice was far simpler: for an orchestral sound, choose Bach. Today, the choice is very difficult for any student. By the time a person becomes a "pro", s/he will know what s/he wants in and out of a horn, so the choice can be narrowed. Overall, new horns are of much higher standard than the old beaters, for virtually all brands. But some pros want a certain performance. For students, the choice is usually between old or new, and then limited by price.
