Pianistic preferences

I am called upon to perform on both digital and acoustic pianos about equally in my working life.  Naturally, I press the keys on whatever is put in front of me without quibble, but if there is a choice I will always plump for a traditional acoustic piano. I have sometimes been questioned as to why, and at times this can appear a counter-intuitive option (I have played some pretty ropey pianos over the years) so I wish to make a case for why the traditional acoustic instrument is, at least in my experience, preferable to modern electronic keyboards.

We must begin by stating that electronic keyboards in general posses the following advantages:

1. They do not go out of tune.
2. If the function is supplied, they can be re-tuned to mean, Pythagorean, modal temperaments and baroque pitch at an instant.
3. They are not susceptible to changes in temperature, humidity and movement in the way an acoustic piano is. In fact the only possible damage from these factors would be water ingress causing short circuiting.
4. They are usually equipped with a moderate-to-wide range of timbral possibilities, albeit synthesised. This is probably the most significant advantage of the instrument.
5. Other useful functions such as transposition and recording capacity are often fitted.
6. They are cheaper to purchase, smaller and more portable than traditional pianos.
7. On high-end instruments, the key and pedal action is weighted in an attempt to imitate that of an acoustic instrument, aiding the traditionally trained player. 
8. They are easier to amplify as a PA system can be plugged directly into the instrument without the need for a microphone.

With all this in mind, one might wonder why anyone bothers with traditional pianos any more. By comparison, they are expensive to purchase and maintain properly, are difficult to move, can only produce one sound 'patch' and have no 'performance aids' other than three pedals and that the stool adjusts up and down.  Electronic keyboards work on the same principle as other electric instruments such as guitars: by creating a tiny sound (in this case small bars which are struck like chimes by the keys) and amplifying it, usually modifying the resulting wave as well. This means that a lot of delicate and temperamental components can be eliminated and replaced by circuitry. So why do I still prefer a 'real' piano?

Firstly, the instrument has a richness and sonority that is impossible to imitate digitally. Chiefly this is due to the effect of the strings vibrating in whatever acoustic space the instrument is played in, but also to do with the fact that the strings vibrate in sympathy with each other. The reason why this is nearly impossible to synthesise is that the additional overtones created thus, which depend on so many multiple factors - the exact notes played and the attack of each, what degree of pedals are being used, what strings may still be vibrating from the previous combination of pitches - that the memory and processing power required to store and activate the sample of each possible combination would be in the range of a supercomputer.  Even then, it is a difficult task indeed to make what is essentially an amplified glockenspiel sound like felted hammers hitting sets of metal strings.  The tone of electric pianos is almost always too fuzzy and boomy by comparison (a common problem with amplified instruments) and lacks the crispness one can get from a well-practiced staccato.  In addition, the percussive effect of the felt making initial contact with the string is difficult to synthesise, often replaced by sound of the plastic key thumping against rubber bearings and electrical contacts.  Pedal action remains a weak area, largely because of the above issue of sympathetic vibration and, on the other foot, so to speak, the fact that an una corda or due corde marking has acoustic implications far beyond simply reducing the volume a bit. I have yet to play a digital piano in which half-pedalling was at all satisfactory, and on most it was impossible as the sustain pedal was considered a binary switch which when on simply added a set amount of reverb.

As an addendum to the above, there are certain pieces which are absolutely impossible to perform on a digital piano as they require this sympathetic vibration as an essential effect. A piece titled simply 'Harmonics' in the fourth book of Bela Bartók's excellent pedagogical series Mikrokosmos is one example, requiring the player to depress keys without them sounding and then allow the strings to be set vibrating when other notes are struck. This simply could not be accomplished on a non-acoustic instrument.

The other, related, consideration is the feedback the player gets from the instrument.  Even the most sophisticated digital key mechanism cannot emulate the action of the 80-or so components that are needed to play even a single note on a strung instrument. When playing a real piano, one can directly feel, even in notes of short duration, something inside the instrument applying force to something else, changing centres of gravity and creating inertia, which provides valuable information on how the note will sound even before the sound reaches one's ears.  Electronic instruments lack much of this vital 'touch' due to there being essentially a short-cut in the action. (For much the same reasons, I dislike driving cars which have too much electronic intervention in the controls).  Furthermore, the key action often lacks sufficient resistance, meaning than when playing fast passages or using the position of one key to find another it is far too easy to accidentally sound the wrong note when passing the hand over it, as well as making chord voicing harder.  All these factors force the player to take time to adapt; whilst the musical results will probably not suffer having done so, it remains that the pianist is essentially learning a new type of instrument.

Finally, another issue which has not been satisfactorily solved by the manufacturers of synthesised instruments: volume. Not the amount of it, for most keyboards and electric pianos have a volume control in addition to touch-sensitive keys which provides more than adequate range, but the guesswork that must be undertaken to find the correct setting.  Of course this can be an advantage, as it allows the relative volume to be adjusted to suit a large or small space, but it is often a source of frustration when the player finds that what seems deafeningly loud to them comes across as feeble at the back of the room. A chief cause of this is that speakers howsoever positioned (usually under the main body or key rack) cannot synthesise a large soundboard reflecting string vibrations in a universal direction. As stated, this is less of an issue when a PA system with large speakers is connected to the instrument - but this instead creates the potential problem of the source of the sound being some distance away from the player and thus not in sync with the action of their fingers. When sitting at an acoustic piano one can always assume, to a reasonable degree of accuracy, what volume any given amount of force on the keyboard will produce.

The pipe organ is, of course, a separate instrument entirely, but has equally valid considerations in the electronic vs acoustic choice. A good full-size electronic church organ is as good as its traditional counterpart, but as far as I can see a small portable organ cannot compete - it'll simply never be as loud without excessive amplification.