Synchronous Scanning of Rolls
By Wayne Stahnke
Hi, there, Robbie:
I have been following the discussion about Mark Fontana's project with interest. One of the things that caught my eye is your suggestion, and the following discussion, about the special requirements for making rolls, deriving fundamentally from the relatively coarse punch advance of paper rolls.
As you know, I have developed a method for scanning rolls synchronously to get the maximum possible accuracy. This method effectively restores the master roll, or what is the same thing, the perforator control file. I developed this method primarily for use with reproducing piano rolls, where the timing is critical. If you listen to a Licensee roll that has been sampled asynchronously, and the same roll sampled synchronously, you will notice a marked difference. The articulation of the synchronously scanned roll is greater, especially in passages where there is close coding for the purpose of accents, or where the melody sings out over the accompaniment.
However, it turns out that synchronous scanning of rolls is equally applicable to 88-note rolls, nickelodeon rolls, and other rolls that were created mechanically for perforating with a relatively coarse punch advance.
In these rolls, the number of punch steps per measure is a "round" number, usually the product of small powers of 2 and 3. QRS was especially fond of using 48 punch steps per measure; Licensee preferred 72. The QRS standard allows the measure to be divided into half, quarter, eighth, and sixteenth notes exactly (with 24, 12, 6, and 3 punch steps, respectively). The Licensee standard allows for half, quarter, and eighth notes ( 36, 18, and 9 punch steps, respectively). In addition, triplets are also possible, also exactly. Dotted figures are usually not perforated as written in score, but rather as triplets; this reduces the harshness of the dotted figure. Note that as late as the 1950s it was traditional to play dotted figures as triplets in the popular music of the time.
I have provided perforator control files for a QRS roll and a Licensee roll through Foxtail. These rolls illustrate the points above, and provide much more information besides. I hope the rolls will be useful to you and Mark, and others who are actively engaged in creating rolls of new music.
Wayne Stahnke
|
(Message sent Thu 11 Apr 1996, 02:32:17 GMT, from time zone GMT-0400.) |
|
|
Mechanical
Music Digest™ Archives
