Greetings,  I have spent some time over the last few weeks writing
a program for the modification of velocity in MIDI files.  It uses
a very flexible mapping approach which allows for the setting of
minimums and maximums as well as linear and non linear scaling.
Just about anything can be done to the relationship between the input
velocities and the output ones.  It is rather like using a linear
equalizer on a typical stereo system.  This allows for matching the
source to the playback device as well as making accommodations for
room sizes and personal tastes and preferences.

The program also has a facility for plotting histograms of the MIDI
velocities in files and several other features that may be useful to
those who want to convert a variety of MIDI files to play better on
their solenoid pianos.  Any number of files may have their histograms
displayed simultaneously (limited by your computer display) to allow
for comparisons.  Some very interesting things can be found in looking
at the histograms of different MIDI files.

The program allows for the creation of presets which can be saved and
can also be shared with others using an import function.

I have done quite a bit of testing of the program but it is still
in development.  Several others have used it successfully and have
provided useful feedback which has been very helpful.  I hope that
I have created a program that is easy to understand and use and that
might help others to get more out of their music.  I am still
interested in feedback and would especially like to hear what sorts
of presets may be useful to others.  If there is enough interest,
I will devote a web page to the sharing of preset files.

The home page of my web site has the information on locating the
program:  http://www.spencerserolls.com/

Best regards,
Spencer Chase
Laytonville, California
http://www.spencerserolls.com/

 [ A histogram is a graph of the number of occurrences in a set.
 [ A hammer velocity histogram shows how many times the piano hammer
 [ was struck with a given velocity.  Histograms of data files of piano
 [ hammer velocities played by a live pianist (or by a well-regulated
 [ reproducing piano) display a smooth graph with few aberrations.
 [ A data file that has been extensively edited generally shows some
 [ spikes because the editor habitually modified too-loud or too-soft
 [ notes to become convenient quantized values.
 [
 [ Histograms are also a very useful tool to quickly display the
 [ quality of a transcribed piano roll, especially if the original roll
 [ is a highly edited pop tune.  A histogram of the paper distance from
 [ one chord to the next displays the sum of the phase jitter of the
 [ perforator plus the jitter of the roll transport mechanism of the
 [ transcriber machine.  Common sources of phase jitter are random
 [ time delays in the computer processing or the commands to increment
 [ the paper position and/or the paper distance accumulator device.
 [
 [ Sometimes a cyclic jitter is observed which can be correlated with
 [ the rotation of a roller somewhere in all the machinery, such as the
 [ capstan or take-up spool.  This is how a problem was discovered in
 [ Richard Tonnesen's perforator system: he found a sticking bearing at
 [ one of the axles supporting the heavy rolls of unperforated paper.
 [ -- Robbie