Bohlen-Pierce Clarinet Project in concert

I’m glad to announce that I will be joining the Bohlen-Pierce Clarinet Project for a concert on sunday February 15, 2015 in Hamburg, Germany.

The Bohlen-Pierce scale uses the twelfth (octave plus fifth) as its harmonic frame, dividing it into 13 steps, according to various mathematical considerations. The result is an alternative harmonic system that opens new possibilities to contemporary and futuristic music.

Lucid Movinguitar The 41-tone system is a very good match to the BP scale as its perfect twelfth (spanning 65 steps) is also divisible by 13: a single BP step equals 5 frets on this guitar. It even provides ‘microtonal inflections’ from the strict BP pitches by shifting one or two frets up/down.

I got in contact with Todd Harrop and Nora-Louise Müller during the EUROMicrofest 2013 in Cologne, and through them I received an invitation from Georg Hajdu for this concert. Exciting!

The following text is from their Facebookpage.

Here comes the Bohlen-Pierce Clarinet Project with quite a bunch of brandnew works! The BP family keeps growing, and we are proud to present an ensemble of nine BP musicians, including three BP clarinets.

Nora-Louisa Müller, Akos Hoffmann and Carola Schaal – BP clarinets
Andrej Koroliov – BP keys
Melle Weijters – 41-tone guitar
Manfred Stahnke – BP/JI viola
Yu-Ching Chao – BP alto recorder
Lin Chen – BP kalimba
Tair Turganov – double bass.

Todd Harrop, Benjamin Helmer, Georg Hajdu, Mandfred Stahnke, Goran Lazarevic, Nora-Louisa Müller, Akos Hoffmann

New to this scale? Read the Very Short Introduction to the Bohlen-Pierce Clarinet below!

BP (Blues Piece)

Well, here it is, my first track on the Lucid Movinguitar. In this improvisation, I use a non-octave scale called Bohlen-Pierce, which is a 13-part equal division of the perfect twelfth (octave+fifth) which happens to be well approximated by the 41-tone system.

For more information about this scale, visit:

Lucid Movinguitar

Shaking of my frets was an act of personal liberation in pursuit of improvisational freedom. However, I took the inevitable study of a couple of thousand years of tuning history for granted. When I was asked to make a wish list for a ‘real’ microtonal guitar, I came up with the idea of a 41-tone equally tempered guitar.

Lucid Movinguitar


On April 21st, 2012 I received this mail from Aaron Andrew Hunt (

Hi Melle!

The Super-Special Ultra-Custom All-Yellow U-Plex is finally done. I think the yellow worked out well. Because of the shade it is, my code name for this project became “the school bus”. Check it out:


I will keep it through the weekend for final testing and packing and then ship it to you on Monday.

I hope you like it!


And do like it?! No. I love it!  Thanks for all the super-special-ultra-customness, it really adds to the coolness of the design and it will blend in my personal environment – including my instruments – really well! Last days I spent some time with the theory of the H-system, so I almost know the nomenclature key by key 😉

So, what exactly is it?

U-PLEX is a class-compliant USB-MIDI controller with 633 keys, two octave transposition buttons, and a 1/4” jack for sustain pedal input. It outputs untuned MIDI data to any application that receives MIDI. Its small form factor and USB connectivity make U-PLEX an ideal choice for making microtonal music with laptop and desktop computers. | Details