Naturinstrumente

Heimatklang

Playable Tones
with the Alphorn

The range of the Alphorn is the so-called “natural harmonic series” with a range of 12 to 16 tones per Alphorn, varying depending on the tuning. The basic rule is: The longer the Alphorn, the more tones are playable!

The Tuning

The tuning or fundamental tone depends on the length of the horn. Short horns have a higher fundamental tone than longer ones. The length of the fundamental tone wave is therefore shorter than in a long horn. This means the frequency is higher and a higher tone is produced.

The conical shape and the bell also have an influence on the tuning. If you determine the resonance frequencies only for the conical tube, you do not get whole multiples of the fundamental frequency for the overtones as you would with an ideally thin tube (see experiments with a hose) with a constant diameter. There is a deviation from the natural harmonic series, other non-harmonic intervals arise. If you determine the resonance frequencies of the entire Alphorn (with the bell), you get the harmonic natural harmonic series. This means that the bell corrects the inharmonic series to the harmonic natural harmonic series. This was measured by Rolphe Fehlmann in 1994.

      The Natural Harmonic Series

      With the Alphorn, you can blow different tones. Depending on how strongly you let your lips vibrate, a higher or lower tone is produced. The pitch of the tone depends on the frequency at which the lips vibrate. High frequency means high tone, low frequency low tone. If you look at the waves, at a higher frequency, more wave crests and troughs are produced in a certain time than at a lower frequency.

      In the Alphorn, these are pressure surges. The faster the lips vibrate, the more pressure surges are produced, and the higher the tone becomes. However, a beautiful tone is not produced at every frequency. You can only play the tones of the natural harmonic series, which are the resonance frequencies of the Alphorn.

      This series begins with the lowest tone, the fundamental tone. A wave is produced with two low-pressure nodes at both ends and a pressure node in between. At the next higher tone, two pressure nodes are produced. It continues like this, each next tone has one more pressure node than the previous one. This means the frequency of a tone is a multiple of the frequency of the fundamental tone. This sequence of tones is called the harmonic natural harmonic series.

      When you play the natural harmonic series, you start with the fundamental tone, the second tone is an octave higher, the next a fifth, then a fourth, and so on. These intervals are the ratios of the frequencies of two different pitches. When playing this natural harmonic series, you immediately hear that some tones sound unusual.

      The 7th, 11th (also called Alphornfa on the Alphorn), and 13th natural tones appear a little too high or too low to us. This is because our ear is accustomed to the tempered tuning. Here, an octave is divided into 12 identical semitone intervals. As a result, only the octave is a pure interval. All other intervals have a slight deviation from the natural tone frequency.

      You especially notice this deviation when you compare the 7th, 11th, or 13th natural tone of the Alphorn with the corresponding tempered tones of a piano. The tones are slightly different.

      The Distinctive Alphorn-Fa

      The Alphorn is a pure natural instrument in its sound. In this characteristic, the natural tones come into their own in a wonderful form. The very special tone is the Alphorn-Fa. It is the 11th tone in the natural harmonic series (see below). The term “Fa” comes from the solfège scale Do – Re – Mi – Fa – So – La – Si – Do. It refers to the 4th tone. The 4th tone in the C major scale is the F. However, the F cannot be played on the Alphorn. If you want to play the tone between E (third) and G (fifth), a “mid-tone” sounds, which lies exactly between E and G. This mid-tone is called “Fa” on the Alphorn. If you narrow down the middle between E and G more precisely, you can determine that the Alphorn-Fa lies between the F (fourth) and the F sharp (tritone). In other words: The Alphorn-Fa is neither an F nor an F sharp.

      The Alphorn-Fa has a special charm. In the past, the Alphorn-Fa was long ostracized by the Swiss Yodeling Association, at least referred to as an “undesirable tone” (sonus non gratus). At the competitions in Switzerland for Alphorn, the Alphorn-Fa was consistently disapproved of. Alfred Leonz Gassmann (see below) used both the Alphorn-Fa and the B in his compositions. This gave the Alphorn tunes a new expressiveness, which in a suitable form triggers a special charm. Today, there are hardly any compositions that do not include the Alphorn-Fa.

      Those who have experienced basic training in wind music find the unusual Alphorn-Fa difficult. The reason is that this Alphorn-Fa “falls” out of the diatonic tone. It is worth trying for a longer time: Play not on the Alphorn for a longer time, but “only” on the trumpet, flugelhorn, or trombone. Then switch to the Alphorn and play the natural harmonic series. You will find that you have a hard time until you get used to the pleasant-sounding Alphorn-Fa again with your lips and hearing. Many listeners – especially from the wind music circles – even think that the Alphorn player is playing a wrong tone. Those who are Alphorn players soon know what expressiveness is in this Alphorn-Fa. In the vocabulary of Alphornists, they consciously speak of the “Alphorn-Fa”. They have almost made this natural tone their own.