Touching the bell in order to locate third—and sometimes even fourth—position is a common bad habit among trombonists. The reasons for this are fairly obvious. When first learning to play young musicians are taught to visually locate some of the slide positions in relation to the location of the bell, and third position in particular lies close enough to it that touching the bell with the index and/or middle fingers becomes a means of ensuring that one has found the right “spot.” Some teachers of beginning students even encourage this practice, unfortunately. A few students will extend this approach to finding fourth position by reaching back with the right thumb, which becomes particularly unhelpful as the student grows and the placement of fourth position moves further and further out as the thumb lengthens.
The problems with this approach are as obvious as the reasons for adopting it. While young students with untrained ears must be taught to locate slide positions using various visual or tactile clues (i.e. judging by the location of the bell or the feeling of a more or less full extension of the arm), the hope is that they will move as quickly as possible to locating slide positions aurally, by the sounds and intonation of the pitches being played. Touching the bell to locate slide positions disrupts this process, as students will essentially shut off the ears in favor of finding positions solely with the hands. As I’m fond of saying “fingers are great, but they don’t hear very well!”
An additional problem with touching the bell is disruption of technique. As students become more advanced and the technical requirements of assigned music increase the impulse to touch the bell when passing third and/or fourth positions hampers the execution of fast-moving passages. While I am ultimately not a “don’t-touch-the-bell purist” (i.e. I don’t usually correct the habit if it occurs only occasionally and doesn’t seem to be causing problems with tuning or technique), when a student’s bell-touching detracts from the quality of performance it must be corrected immediately.
The question is how does one break a student (or oneself) of this habit? Often it goes away on its own as the music becomes too difficult to execute while touching the bell. Likewise, as students’ listening skills improve they become too dissatisfied with the poor tuning when touching the bell to continue doing so. I have occasionally resorted to extreme illustrations like taping a thumb tack or push pin to the student’s bell. This is for illustrative purposes only—I do not actually place the sharp point in a location where the student will touch it and be injured—but it sometimes communicates the message. A less extreme version of this is to modify the children’s game “the floor is lava” and instead say “the bell is lava.” I tried that one just this afternoon with a student and his execution immediately improved. Maybe that’s a healthier visualization than taping sharp implements to students’ instruments!
In the end, bell-touching tends to decrease as students practice and improve. When it persists, this habit is very likely indicative of insufficient practice as much as anything else. A healthy, daily regimen of fundamental exercises and scale studies is called for.
And remind them that “the bell is lava!”