I started my brass playing career about 20 years ago in the fourth grade on trumpet. Unfortunately, I wasn’t taught how to form a correct embouchure and played “in the pink” until my freshman year … of college.
For those of you who are fortunate enough to never encounter this problem, playing in the pink is when the mouthpiece rests on the red part of the lip. It’s more common with trumpet and french horn players, but I’ve seen one or two trombonists play like this.
These days, I play euphonium and once in awhile, trombone though I should have started on a low brass instrument because I have thicker lips. When I was forced to change my trumpet embouchure in college, I had a hellish time. After a couple years, I decided to seriously pursue the euphonium and it’s worked out for the most part. Still, I wonder what may have been had I been coerced into switching to baritone/euphonium in, say, middle school or high school.
Something needs to be done when a band director sees a trumpet player playing with such an horrendous embouchure. One can try to fix the embouchure, but usually that takes time and a great deal of patience. If the band director isn’t a brass player, then the situation worsens.
What I would suggest is moving the player with the troublesome trumpet embouchure to a low brass instrument. Most groups are in dire need of euphoniumists and tubists, and not so much trumpeters. What’s more, the student can transfer fingerings while getting used to reading bass clef. The former trumpet player benefits and the group benefits.
