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By comparing piano roll recording and playback technologies to contemporary

technologies, I aim to determine the limitations and strengths of piano roll recordings. The methods used by Welte, De Luxe, Ampico and Aeolian to make and produce piano roll recordings therefore form a major part of this chapter.

As explained in the Introduction (see page 5), Leikin, Peres Da Costa and Ho make similar conclusions concerning the limitations of reproducing piano rolls. Peres Da Costa refers to dynamics, tone, touch and pedalling;114 Leikin cites dynamic nuances, pedalling, phrase shadings, chord voicings and tone colours;115 Ho questions the accuracy of dynamics and pedalling.116 Roy Howat, when writing about Debussy’s Welte-Mignon piano rolls refers to the ‘system’ being “easily confused by Debussy’s mostly low dynamics and any tendency to work at points of escapement and half- pedal.”117 _{As pointed out in the Introduction (page 6), some writers question the} reliability of a piano roll recording because of the potential to edit the recording.

Howat also regards the playback instruments as a source of potential error,

particularly in regard to tempo, citing two Welte-Mignon instruments that gave different playing times for the same roll. He concludes that the multitude of hidden variables that affect what we hear from rolls is “probably dominated above all by the condition and fine-tuning of the replaying instrument and mechanism.”118

My experience with piano rolls and associated pianos has convinced me that the limitations are not always as significant as some writers suggest. As Howat recognises, more often the condition of the play-back instrument is a significant factor affecting the reproduction. Reviewers of audio recordings made of piano rolls played on original instruments have often noted the poor quality of reproduction. Therefore, it is important to look at roll recordings separately from the instruments that play them.

Concerning the instruments, the benchmark is today’s player piano technology, which encompasses a range of systems with different levels of sophistication and

capabilities. My experience is that a well-adjusted pneumatic reproducing piano has a performance capability equal to many modern MIDI player pianos, implying that the data on piano rolls is similar to the data stored in computer files that play on modern instruments. Of particular interest is the type of data that is not recorded on a piano roll when compared to a recording made for the most advanced contemporary player piano.

Determining how the data stored on a piano roll was obtained is especially

important. Some aspects of the recording methods used by piano roll companies remain unpublished, and because the four companies under examination in this thesis had different recording and production techniques, I examine each one separately.

Background – playback technologies

The first pianos that could be played mechanically date to the early 1800s and had a rotating barrel to actuate the piano keys.119 Roll-playing instruments began to appear in experimental form during the latter half of the nineteenth century, culminating in the Votey ‘push-up player’ described in Chapter 1, which was marketed as the Pianola by Aeolian from the late 1890s. The reproducing piano took piano roll technology to its highest form by introducing dynamic control of playing notes from expression data stored on the roll.120 It was not until the late 1970s that this technology was superseded, when the Pianocorder produced by US company Superscope was first marketed.121

Unlike pneumatically-powered players and reproducing pianos, the Pianocorder player system used electrical power to operate solenoids to play the piano keys. A solenoid is a coil of wire wound on a cylindrical former which houses an iron core. The core moves due to the magnetic field set up by the coil when an electric current flows through the coil. The velocity of the moving iron core, and therefore the volume of playing notes can be controlled with electronic circuitry. The Pianocorder played from recordings stored on cassette tapes, with much of the recorded material derived from piano roll recordings. It was the first break from the traditional pneumatic technology found in virtually all player pianos up until that time.122

119 _{Bowers, Encyclopedia of Automatic Musical Instruments, 364.}

120 _{The operating principles of a pneumatic reproducing piano are examined in Chapter 3.}

121 _{Mark Andrew Fontana, Preservation and MIDI Translation of the Pianocorder Music Library,} http://pianocorder.info/pdf/mark_fontana_thesis.pdf (accessed 21 October 2015).

122 _{Solenoid-powered player pianos with limited expression capability were manufactured in the early} 1900s, such as the Electrelle player system mentioned in Chapter 1, and the Telektra system.

In the mid-1980s, Yamaha began marketing its version of a player piano, called the Disklavier. Like the Pianocorder, the playback system consisted of solenoids, but unlike the Pianocorder, the Disklavier conformed to the MIDI standard (see below), which had been established a few years before and remains current today. To ensure it had the entire market, Yamaha purchased the company producing the Pianocorder and closed its operations. A consequence was that a US-based company affected by the loss of sales of the Pianocorder went on to develop the PianoDisc MIDI player system, which is now the Disklavier’s largest competitor.

MIDI-based solenoid player instruments are analogous to pneumatic reproducing pianos in that both types have similar playing characteristics, as explained later. It is only the high-end instruments that take playback technology to a higher level. High-end MIDI solenoid pianos

Solenoid player pianos that can reproduce a pre-recorded performance with a high degree of accuracy began with Wayne Stahnke’s SE instrument, marketed by

Bösendorfer during the late 1980s.123 Yamaha began marketing its Disklavier Pro series of MIDI solenoid pianos in 1998. The current range of Pro instruments can

demonstrably record every aspect of a pianist’s playing, and reproduce the performance with an almost absolute accuracy.124 Other instruments with similar specifications are Bösendorfer’s CEUS-equipped series of pianos.125 _{The SE instrument has since been} developed further by Richard Shepherd in England and is used in special projects, but is no longer commercially available.

There is little information that details the operation of high-end mechanical player pianos. Yamaha provides a website that outlines aspects of the company’s Pro series, explaining that “the Pro models are distinguished by key sensors, pedal sensors,

hammer sensors, moving magnet sensors with key sensor servos, […] and the ability to record and play extended precision MIDI data, known as XP data.”126

The complexity of a high-end mechanical player piano is associated with its

ability to accurately control a relatively simple solenoid to recreate the movement of each piano key. Although this technology is best exploited by recordings made on the particular instrument, it also ensures a high accuracy of playing of a standard MIDI file.

Background – recording technologies

Prior to the introduction of hand-played roll recordings, rolls were produced

mechanically from a score by marking lines on a stencil which was later punched to become a master roll. It is probable that the first piano roll recordings to qualify as being made by a live pianist were produced for the Welte-Mignon in 1904, as described later in this chapter. In 1905, Hupfeld introduced the Artistic Hand-Played Music Roll, a series of piano rolls for the company’s Phonola player piano.127 Dynamics were shown only as a wavy line along the length of the roll, however the pianist’s tempo-related nuances were now captured on the roll.

As later explained, the Welte recording system not only recorded note pitches and durations, it also recorded the dynamics of each note, as well as damper and soft pedal operations. Following the introduction of the Welte-Mignon, other companies sought ways of recording piano dynamics. Unfortunately, the only documented method is that used by Ampico after 1926.

The biggest limitation of piano roll recording technology is that the owner of a reproducing piano could not themselves make recordings for the instrument. The Pianocorder was the first mechanical player piano to incorporate a recording system. Contacts under the keys provided signals which were recorded on cassette tape using a data format developed by the company. The dynamics were recorded by a microphone that hung inside the piano. The results, though often quite poor, represented a new approach to making recordings of a live pianist for playback on a mechanical piano.

The recording technologies used in the Disklavier, PianoDisc and other systems differ in their implementation and accuracy. Importantly, all these systems conform to the MIDI standard.

The MIDI standard

The MIDI standard supports a 128-note keyboard and 127 dynamic levels, called ‘velocity’ levels. The loudest level is 127, the softest is 1, and level 0 means the note is 126 _{George F. Litterst, Anatomy of a Disklavier, http://yamahaden.com/anatomy-of-a-disklavier (accessed} 19 April 2016).

turned off. When a key is depressed on a MIDI keyboard, the resulting MIDI data, called note data, comprises a standard digital code for that key and a velocity level expressed as a digital value.128 When the key is released, the resulting note data now has a velocity of 0. That is, MIDI note data controls when and how loudly a key is played and how long it remains held.

MIDI control data operates the pedal actuators. In its simplest form, a MIDI code with a position value of 127 turns on the solenoid operating a pedal, and a position code of 0 turns the solenoid off. This type of pedal data, called on-off pedalling, causes the solenoid to move through its full stroke and is the arrangement used in MIDI player mechanisms made by PianoDisc and other companies. A more precise system, called positional pedalling is fitted to Disklaviers, in which position codes other than 0 and 127 cause the pedal solenoid to move to a position between its two limits.

There are numerous other functions supported by the MIDI standard, but in the case of a mechanical player piano playing from a MIDI file, note and pedal data is all that is generally required. The simplest form of MIDI file of a piano work has only note and on-off pedalling data, which is the same information stored on a reproducing piano roll.

In a high-end instrument, the number of velocity levels (note dynamics) is far greater, 1023 in the case of the Disklavier Pro. Interestingly, some types of pneumatic reproducing pianos have an almost infinite number of velocity (dynamic) levels, due to the way the expression regulators work. All brands of high-end instruments use a proprietary form of MIDI and recordings made on a high-end MIDI instrument therefore contain data unique to the instrument. As Yamaha further explains about its Pro series: “Disklaviers use sensors under every key as well as advanced gray-scale sensors on the hammer shanks in order to determine the timing of notes, the velocity with which the hammers hit the strings, and the speed of the release of each key.”129

A consequence is that the recorded data in a Pro-equipped Disklavier holds

positional information about each key. I have noted that keys can be held in a fixed

position, or are caused on replay to move only part way through their total travel. Brushed notes will be reproduced as they were played, in which the hammer moves but

player pianos, both in terms of the instruments and the data that is captured by recordings made on these instruments.

MIDI solenoid and pneumatic reproducing pianos

As previously explained, a reproducing piano roll contains the same data as a standard MIDI file, assuming on-off pedalling. Differences between the instruments include how the data is read and interpreted. Both MIDI solenoid and pneumatic player pianos operate in a similar way, but with different forms of energy. In both cases, keys are actuated mechanically, and the actuators are turned on or off by the data in a MIDI file or, in a pneumatic piano, by perforations in a piano roll. The velocity of the actuator in either type of instrument is determined by the velocity data in a MIDI file or the expression perforations on a piano roll.

A difference between the technologies is that unlike MIDI pianos, pneumatic reproducing pianos do not have individual dynamic control over each key. Instead, the keyboard is divided into treble and bass sections, with a regulating mechanism

controlling each section, which means only two dynamic values can exist at any one time. The point at which the keyboard is split differs between piano roll manufacturers, and is generally a few notes up from middle C. Roll editors used various techniques to make thematic notes sound louder than accompaniment notes when both shared the same part of the keyboard. Methods included advancing a thematic note by a few perforator punch steps, so that the note could be individually accented, but causing the note to be heard slightly ahead of accompaniment notes.

Another difference is the number of notes covered by the player mechanisms. A MIDI mechanical piano has a compass of 88 notes, but most reproducing pianos have a slightly smaller compass, as detailed in Chapter 4.

Pedal data on piano rolls is always on-off. Even so, there are instances where the time between damper pedal perforations on a roll would be insufficient to allow a pneumatic actuator operating the dampers to move through its full travel. On some instruments the slow operation of the actuator might give a form of half-pedalling. The soft pedal in most of the reproducing pianos (grands and uprights) that I have observed is of the half-blow type, in which the pedal moves the hammers closer to the strings. This arrangement has the advantages of being light and quick to operate, ideal

characteristics for a suction-powered player system. There are a few reproducing grand pianos in which the soft pedal actuator operates the instrument’s una corda pedal.

Summary

As a playback instrument, a pneumatic reproducing piano has similar characteristics to a standard MIDI solenoid piano. Both types of instruments play from recordings that cause each note to be played at a specified volume, and both incorporate a means of operating soft and damper pedals in response to the recorded data. A reproducing piano roll stores the same data as a standard MIDI file.

Limitations of piano rolls

The main limitation of a piano roll recording is the lack of data controlling key and pedal positions. Because key release speed is not recorded, passages that rely on keys being partially pressed during playing will lack particular nuances. Although the tonal effects created by positional pedalling techniques were not recorded, roll editors were aware of the limitation and, as later explained in Chapter 4, in some cases attempts were made to recreate lost effects.

A critical aspect of a piano roll recording is the accuracy of notes and their timing in relation to each other. While the original recording might have recorded the notes extremely accurately, the quantising that occurs during perforation of a production piano roll means the timing resolution is reduced, a factor that is examined when discussing each brand of piano roll.

The greatest unknown with reproducing piano rolls is how the expression data was derived. As this aspect of a reproducing piano roll is the differing feature between it and any hand-played piano roll, it is an important consideration. It is also the least

documented, as later explained, leading researchers to generally conclude that the dynamics of a reproducing piano roll are unreliable.

Therefore, when examining piano rolls as a form of recording, factors to consider are note timing accuracy, the extent of pedal information, the potential accuracy of the dynamics and the extent of editorial change to the original performance. These factors are associated with the piano roll.

The playback instrument is responsible for reproducing the performance recorded on a piano roll and therefore determines, among other things, the sound quality and

piano. Most reproducing pianos were either uprights or small domestic grands, although Ampico, Duo-Art and Welte mechanisms were fitted to full-size concert grand pianos for special purposes. Therefore, a limitation of a piano roll recording, and a MIDI file, is that tone is not recorded and is only reproduced accurately if the recording is played on an identical piano to that used to make the recording.

Another factor that is difficult to quantify is the difference between a master roll and the production rolls produced from that master. Therefore, it is only possible to refer to the potential accuracy of a piano roll recording, while acknowledging that production rolls may have errors caused by the duplication process. The types of error depend on the process used to cut production rolls, in which as Stahnke explains, can involve either of two types of masters, and which he refers to as ‘prototype’ and ‘pattern’ rolls. Stahnke concludes that most production rolls in the US were produced using pattern rolls, in which sprocket holes either side of the paper caused the pattern roll to move reliably and in synchronism with the paper being perforated, giving the best accuracy.130

Welte-Mignon piano rolls

As listed on page 21, there are three types of rolls associated with Welte-branded instruments. Those for the Welte-Mignon are the most significant, as rolls for the Licensee (other than those made by De Luxe) and Green Welte instruments were derived from them. Little is known about the processes used to record Welte-Mignon rolls. The only surviving example of a recording machine used by Welte is held by the Museum of Music Automatons in Seewen, Solothurn, Switzerland. The machine was used to make rolls for the company’s range of pipe organs, and probably also for the Welte-Mignon.

Note recorder

A photo of the Welte recording machine, included with David Rumsey’s description of the machine,131 shows that it has a number of inked rubber wheels poised near a roll of paper such that when a key was played, it caused the corresponding wheel to contact the moving paper. As a result, an inked line would be marked on the paper while a key was

130 _{Wayne Stahnke, Prototype Rolls and Pattern Rolls,}

http://www.mmdigest.com/Archives/Digests/199708/1997.08.27.17.html (accessed 22 October 2015).