Sarah Willis, the first female brass player in the Berlin Philharmonic, an incredible low horn player, and the host of several music- and horn-related TV and internet shows, has done an incredible experiment on what goes on inside the mouth while playing horn by playing a specially-made horn inside an MRI machine!
The full video (available here – it’s only 12 minutes, and you can skip to about 5:30 for the good stuff) shows not only the action during articulation, but also the function of the tongue with regards to high and low range, and varying dynamic levels.
The results of this experiment really tie in well with an exercise that I’ve been doing lately with many of my students – trying to blow the air (in a kind of half-whistle) at a speed where you can almost hear the pitches you are intending to play. This works especially well for slurring medium to large intervals either up or down.
As an aside, if you are a horn player and you haven’t heard of or watched any of Sarah’s Horn Hangouts videos, you really should check them out. She’s doing a great job of using technology to get interview some of the greatest and most famous horn players, brass players, and others! She’s got interviews with Phil Myers (principal, New York Phil), Julie Landsman (former principal, New York Met), Dale Clevenger (former principal, Chicago Symphony), Radovan Vlatkovic (soloist), and many, many others.