Introduction --

I always liked to design and make myself any kind of mechanisms and
electrical and electronic equipment. Starting at the age of nine I have
been making radio receivers, transmitters, electric vehicles, hi-fi
equipment, etc., and especially, musical instruments, including pipe
organs.

When I discovered player and reproducing pianos some 20 years ago,
I loved them at once. I acquired knowledge of pneumatic technology and
I restored many player and reproducing pianos (Duo-Art, Triphonola and
Welte) and made various instruments and devices, such as:

  Reproducing push-up capable of playing Duo-Art and Triphonola rolls
  Electro-pneumatic attachment for player pianos, with MIDI interface
  Roll reader, with MIDI conversion, for standard and Duo-Art rolls
  Electric push up for acoustic piano
  Converter of Triphonola rolls to Duo-Art
  Recording and self-playing pipe organs
  Push-ups for ancient tracker pipe organs, Internet concertos.
  Other self playing instruments (harpsichord, accordion, harmonium,
    vibes, xylophone)
  MIDI orchestrion with pipes, xylophone, and percussion instruments
  MIDI rhythm machine (a complete drum set, playing jazz, Latin, etc.,
    with other instruments).

I knew the existence of Mills Violano and Hupfeld Phonoliszt-Violina.
So, why not make a self-playing violin similar to those machines?
The wide availability of MIDI files with good violin performances would
make the job easier.

Experimentation and technical information --

I decided to make a machine similar to Mills Violano, being much
simpler than the Hupfeld instrument.  The use of electromagnets,
instead of pneumatics, would make possible a more compact and simpler
machine.

I soon understood that one of the critical matters of the job were the
bow wheels.  I tried various materials (wood, rubber, plastic, metal),
but the sound and its attack was poor.  The bow wheels could not
emulate a real violin bow, that uses horse hair to provide many tiny
rubbing points.  The original bow wheels, and the ones by Ralph
Schultz, use many extremely thin and highly flexible plastic discs.
It would be difficult for me to make them, so I had them made by Ralph.

Another problem was to emulate the human finger fretting the strings.
An imperfect fretting would produce bad sound, overtones, harmonics.
I avoided to fret the strings from under them, like it happens in the
Mills Violano, because this would have required important modifications
in the violin.  So I put metal fingers fretting from above, but they
did not work properly, because the vibrating strings were not
sufficiently stopped by such metal fingers.  So I used soft plastic
on them to act as a brake for string vibration.

The compass of the instrument is 48 notes, G3 to F#7 -- higher than
the Violanos span in order to give a better performance of virtuoso
pieces using very high treble notes.  The first three strings produce
only seven notes each.  This is a big simplification but it does not
cause important limitations, because no note is missing in the scale.
Only some two-string chords in some piece would be skipped, or could
require editing of the MIDI file to make them play.

The distance of the fingers to give the correct musical scale was
calculated by a computer program.  The distance between the fingers
decreases as pitch increases, and is very small at the top of the
scale, requiring high precision manufacturing.

The performance is made more realistic by a vibrato device: a strong
solenoid shakes the violin tail piece, acting automatically and
gradually after an initial delay, so to affect only the long duration
notes.  The bow wheels are rotated at very low turning speeds of 100
to 300 rpm.

The self-playing violin is controlled by a MIDI decoder and can play,
from MIDI files, any type of solo and ensemble music, with the
accompaniment of a player piano (with MIDI interface) or a Yamaha
Disklavier, or an electronic sound generator, or other MIDI
instruments.

I am now studying a cello and a bass viol to play with the violin.
In the future I might also make a string quartet (two violins, viola,
cello).

Thanks to --

I have to thank Robbie Rhodes and the MMD, by which I learned many
things about mechanical music.  A special thanks to Ralph Schultz, an
expert restorer of the Mills Violano, who built for me the bow wheels
and gave a lot of technical information.  Thanks also to Silvestro,
here in Rome, Italy, for the useful advice and the accurate making of
some important mechanical parts, such as the bow wheel shafts.

Leonardo Forti
Rome, Italy
leonardo.forti@virgilio.it

 [ MP3 audio files and a photo of Leonardo's violin are at the
 [ MMD Sounds site, http://mmd.foxtail.com/Sounds/  -- Robbie