# How many octaves does a scale contain?

## 13-tone music Unfamiliar sounds in a new sound system

Nora-Louise Müller plays a clarinet specially developed for the Bohlen-Pierce scale. (Nadine Dietrich)

Twelve-tone music was yesterday, a real avand-garde composer in the Bohlen-Pierce scale. It has 13 tones and stretches the usual semitone steps. This requires new ways of composing and, above all, new instruments. Pieces in this tone system have now been performed in Hamburg.

Georg Hajdu: "In natural science, many people talk of parallel worlds, new planets that could be habitable, of a super-earth ... For us it is like a new world, new sounds, a way out of this cycle, with the recycling of sounds that have been heard forever, that has the charm of the new, is at the same time beautiful. "

Georg Hajdu, professor of multimedia composition at the Hamburg University of Music, raves about the Bohlen-Pierce scale. The Hamburg technician Heinz Bohlen developed it in the 1970s.

Heinz Bohlen: "I wanted to find something that offered an alternative. You don't always have to do the same thing, there are other options. "

During sound recordings at the Hamburg University of Music, Heinz Bohlen noticed that the musicians always played the same tones on the same scale, in short: they stayed in the traditional, western tone system. Why they did that and exclusively, no one could explain Heinz Bohlen.

"I'm unmusical, don't play an instrument, otherwise I wouldn't have asked such a naive question, you have to ask the naive questions, otherwise nothing new comes along."

### Intervals according to mathematical criteria

The clarinetist Nora-Louise Müller explains the new tone system:

"In the normal scale we have the octave as the frame interval, C and C from the C major scale.

And that octave is divided into twelve semitones if we were to play the white and black piano keys. With the Bohlen-Pierce scale, the frame interval is different. We use the so-called duodecime, which is an octave plus a fifth. So about one and a half octaves, and this interval is divided into thirteen steps from a certain mathematical point of view, we play with almost the same number of pitch steps over an interval one and a half times as wide. "

The usual semitone steps are thus stretched. All 13 tones of the new frame interval sound like this:

Music BP scale up and down.

### New instruments

In order to be able to play pieces of music in the Bohlen-Pierce scale, strings have to retune their instruments. With recorders, the existing holes can be sealed and new ones drilled - it is almost impossible on all other instruments. In the case of the clarinet, an extra Bohlen-Pierce instrument was developed. Nora-Louise Müller owns two of the world's nine clarinets:

"In comparison: Bohlen-Pierce clarinet has significantly fewer keys. Very simplified clarinet, looks like children's clarinet, but they would be disappointed because you can't play any well-known songs on it:"

Nora-Louise Müller and Professor Georg Hajdu recently developed a notation standard so that composers can even write new works with this tonal system:

Georg Hajdu: "We had to think about using new note names so that we don't mix them up: they now start with N and end with Z. Nora and I have given extensive thought to how best to represent the Bohlen-Pierce scale, Then we came up with six lines, that was Nora's service. Then we systematically developed new keys and simply developed a standard. "

### Different reactions

Seven Bohlen-Pierce compositions were presented in Hamburg yesterday evening. Interestingly, the otherness of the tone system could be heard particularly clearly in a piece of music that resembled more conventional compositions - in the piece by the Lübeck clarinetist Akos Hoffmann.

The musically very well-trained audience perceived the Bohlen-Pierce scale differently:

"I really liked the more complex pieces, some of the music of the spheres. There are some things in modern music that I can't hear much different from other pieces of new music."

"It's a bit unusual, but you can't stand still, it's a bit too exhausting to hear it all the time, I think it's just fun live."

"I found it very exciting to hear this strange scale in pieces, I am a composer myself, there were very exciting atmospheric sounds."