The Theory Behind Stopping The Horn

In honor of releasing his newest CD, “No Limits”, Frank Lloyd has put together three different videos describing his playing and I thought his video about hand-stopping was quite interesting.

Hand-stopping – How AND Why

In the video, he describes a bit about the specific technique of hand-stopping, but he goes into quite a lot of detail about what exactly happens to the sound when you stop the horn.

It should go without saying that good hand-stopping relies on good right-hand position, so if you are unsure about your right hand, make sure you get that straightened out first!

First, here’s the video:

He gives a brief overview of the general hand-stopping technique, but if you want the really interesting stuff, skip ahead to about 4 minutes in.

The Hand-Stopping Debate

In brief – there were two theories about what happened acoustically during hand-stopping:

  1. Closing the right hand “cuts off” the bell tubing from vibrating, causing the horn to be a bit shorter, which raises the pitch about a half-step. This is the “pitch rising theory”.
  2. Closing the right hand causes the pitch to drop to one half-step above the next lower harmonic. I’ll call this the “pitch falling theory”. This is a bit confusing to describe, but this image makes it pretty clear:frank-lloyd-stopped-horn

In either case, fingering the notes one half-step lower on the F-horn would “fix” the pitch.

Settling The Stopping Debate

The “pitch rising theory” has been around for a long time, in fact, it’s the theory that is mentioned in Phil Farkas' Art of French Horn Playing. At about the 6:30 mark, Frank mentions hearing about the pitch dropping theory from Richard Merewether, a great acoustician and horn player who designed horns for Paxman for many years, and it was definitely a “fringe” theory for a long time.

I’ve heard this “falling pitch” theory a little, but at about 8:45 Frank demonstrates an ingenious way to test the “falling pitch hypothesis”. I don’t know if the got this exercises from Merewether or made it up himself, but it’s ingenious. This exercise is a great example of how important it is to know your harmonic series for all your fingerings!

At the 12-minute mark, he also demonstrates the “falling pitch” theory using much higher harmonics – up to the 16th and above – where a half-step above the semitone below ends up being the same note (more or less). At 18:45, he discusses the challenges of hand-stopping in the lower register (and also mentions why you rarely see the D-above-middle-C written for natural horn).

All-in-all, this is a great video for anyone confused or interested in understanding (and getting good at) hand-stopping.