Crumb Black Angel (1970)
Subharmonics and A.L.F’s are relatively new and not really understood. With the correct bow placement, pressure and speed then it is possible to perform an octave below the fundamental. For example playing an open G on the violin with a frequency of 196Hz then performing a subharmonic of this creates an octave G at 98Hz. Using this technique it is possible to play all the notes in the octave. This technique was one of the hardest for me to get to grips with as there are so many different variables that affect whether it is possible to play or not. The bow has to be at the correct speed, the bow has to be at the correct pressure and it had to be at the correct position along the string. I also found that it was easier on some violins than others, for example I found that it was much easier on my lecturers violin than my own and I think that was because my violin the tension of the G string was less so it would be much more difficult for it to ‘catch’ the subharmonic.
To play this technique there seems to be 3 factors mainly at work:
1. Bow pressure
2. Bow speed
3. Bow position
Lots of consistent bow pressure is needed, basically as much pressure as you possibly can. Start off right at the heel trying to get the crunch sound, then try to maintain that same pressure throughout the full length of the bow, meaning that you will have to apply much more as the bow reaches the tip. I found that holding the bow at the frog helped to get much more leverage and pressure.
The bow has to be a consistent slow bow, too fast and you will not get or you will loose the subharmonic. Too slow and it will not be an even pace and you will not get the subharmonic.
This will differ slightly depending on your violin but I found that playing close to the fingerboard, about 1 – 2cm away was the best position on the violins that I tested.
It must be noted that you can only play subharmonics on the G string as the pressure needed and the angle of the bow means that the G string is the only option.
George Crumb was the first person to compose for subharmonics in Black Angels calling them pedal tones. He used them to depict the devil in one of the movements.
A.L.F’s are related to subharmonics but are not true subharmonics. Mari Kimura has mastered this technique and people compose pieces containing subharmonics specially for her.