In the 20's there was the Telektra player that played brass rolls of music in a cassette. It was ingenious but most of us have never even seen one
In the 60's Wurlitzer built a home model player piano that played the piano using solenoids that were fired by tiny contacts built into the tracker bar which was the only part of the piano that used suction from a small suction pump. It played normal piano rolls and many of them are still functioning. The main problem with them is the transformer in the bottom of the piano stays on 24/7/365 unless you unplug the piano from the wall. This transformer burns out and must be replaced. Some ill informed technicians spray WD40 or other "lubricant" into the trackerbar. This is the other most common problem. When this is done the tracker bar must be dismantled and cleaned. They also tend to burn out solenoids if marimba rolls are played too long at a time.
In the late 70's Teledyne built an electronic solenoid operated piano playing system that played from a tape and was sold by Sony/Superscope/Marantz. It was named Pianocorder. This was a successful player system for over 12 years, but the Dollar to Yen ratio was too unstable for the company to afford to advertise enough to really sell what they should have. The system began to catch on from word of mouth by 1989-90, but then, Yamaha, wanting to promote their new Disklavier player system and following the time honored tradition of predatory capitalism, purchased Pianocorder in order to put their only competition out of business. The Pianocorder system is a really good system and the many units that are out there will last a long time. I have had very little technical trouble with them if they were installed correctly. Parts are still available, but it is all made from discrete components available from any electronics supply. Their drawback was the installer had to do extensive engineering. I was able to perfect a technique that allowed for far greater spectrum of volume levels, but many installations, I have worked on installed by others, demonstrated to me that they often did not understand the system. I will tell you the secret, since the system is no longer available. I was able to get whisper soft pianissimos out of the Pianocorder because I put the solenoid rails in the grand as close to the capstan line as possible. This means in front of the back rail and its felt. The solenoid rail must be dropped in order to regulate the piano action but the musicality of playing achieved makes it worth the extra trouble for the technician.
After Pianocorders were no longer available and since Yamaha would not sell their retrofit kit in this country, another company came out with the PianoDisk player system. This system was a seat of the pants attempt at updating Pianocorders and played from a floppy disk. For the first several years their system blew up and smoked solenoids at every opportunity. Having installed several hundred of these systems, I watched their development with interest. However, I wish they had not made me feel like they used me and my customers for their research and development. After many updates in hardware and software, their present system is much improved, but it is at the mercy of the person installing it, just as Pianocorder was.
The latest system to be designed and built has, in my humble opinion, also become the most dependable and was built to be the most versatile. I refer to the QRS Pianomation MIDI System. This trouble free system is capable of more musical expression that any others and will play from more sources that any other system. This is the only system that is completely remotely controlled, since it normally has no media storage device attached to it at the piano. Under normal conditions it plays from your own existing CD player which may be situated anywhere in the house with or without wiring. It also plays from CD-ROM. It can play from an audio CD, audio cassette tape, VCR sound channel. Digital MIDI sequencer, floppy disk, electronic keyboard, Computer MIDI software, Hard Drive, Zip Drive, etc. Basically, if it can store audio analog or digital information then it can play a Pianomation. If it is a MIDI device then it can also be played by the Pianomation as well. The Pianomation installed in a high quality acoustical piano can be made to control the console of a completely digital recording or composing studio. One could, without wiring, have 5 or more pianos around the house all playing the same notes at the same time using their wireless remote system. The system can also be configured as a nickelodeon with the percussion instruments added.
There was also a very high-end electronic reproducing player piano system, with record and playback, that was installed on Bosendorffer grands for a few years, but there were just around fifty of them ever built. I refer to the Bosendorffer SE (for Stahnke Electronic) which was designed by Wayne Stahnke. This system was way overkill compared to all the other systems including the pneumatic systems. While most reproducing player systems had from 8 to 32 to 126 volume levels, The SE system has 1024 volume levels. It was used to make the very popular "Window in Time" Rachmaninoff CD's and is something that every player piano groupie would like to have. The only problem is they are no longer in production according to Bosendorffer reps, and they were costing over $100,000.00 when they were new. I must admit that it is way out of most folks' budget, including mine.
There are other new player systems that require investigation, including a new one from Wayne Stahnke and a couple others but I have not had the pleasure of hearing any of them yet.
Perhaps one of these companies will give me one so I can review it.