Unweighted is fine if you're making synth sounds. And of course for understanding the things you've listed.
But you can't actually play emotionally expressive piano music on them -- not in the style of classical or jazz. If you tried to play the Moonlight Sonata first movement, it would sound terrible, because the dynamic shadings couldn't be done.
I'm not really sure how you've determined what "core skills" are. Sure, if your kids are only going to spend a couple years learning the very basics, and then move onto other things, then it's fine.
But the heart and soul of piano music is in the precise touch to generate the dynamic sensitivity. If you want them to learn how to be emotionally expressive through music, playing either classical or jazz, weighted keys are essential. It's not piano otherwise -- it's a synth.
(And going from unweighted to weighted isn't trivial. It's an entirely different muscle memory that needs to be developed. They're fundamentally different instruments.)
Yes you can, and yes it is more-or-less trivial. With a small amount of deliberate practice, you can learn to produce a full and finely-gradated dynamic range on either a piano-weighted or a semi-weighted keybed. It's a one-dimensional mechanical skill that just isn't particularly difficult relative to, say, an oboeist's reed control or a violinist managing the very complex relationship between bow and string. If I say "you just don't press quite as hard" it'll sound like I'm being glib, but that's literally all there is to it, because physics.
Strings players choose from a wide range of string tensions and woodwind players choose from a wide range of reed stiffnesses, based purely on their own personal preference. Some prefer something soft and pliable that responds to the lightest touch, others prefer something that fights back when you dig in. It's an accident of history that mechanical pianos fall into a relatively narrow range of weightings, not a deliberate choice on the part of pianists or piano makers - the range of options are limited by the mechanics of an escapement and hammer.
Pianists overwhelmingly prefer weighted keybeds out of habit, but more generalist keyboard players will often prefer a semi-weighted keybed for versatility. You can play gigs or sessions with either and you're the only one who's going to notice. Calling either choice wrong is just dogma.
> Yes you can, and yes it is more-or-less trivial. With a small amount of deliberate practice, you can learn to produce a full and finely-gradated dynamic range on either a piano-weighted or a semi-weighted keybed. It's a one-dimensional mechanical skill that just isn't particularly difficult relative to, say, an oboeist's reed control or a violinist managing the very complex relationship between bow and string. If I say "you just don't press quite as hard" it'll sound like I'm being glib, but that's literally all there is to it, because physics.
Pretty much every piano teacher on the globe would like to have a word with you. The idea that it's a "one-dimensional mechanical skill" is greatly misleading when it has to do with joints in the fingers, wrist, elbow, shoulder, even your spine. Positions of all those things, varying degrees of muscle tension. And it's incredibly difficult -- pianists spend years improving their touch, and do things like Alexander lessons to eliminate muscle tension that interferes. "Don't press quite as hard" is incredibly complex, physiologically. (And oboeists are only playing one note at a time, violinists one or two -- pianists need to learn to independently control the force of all 10 fingers independently, sometimes all at once!)
But if you want to understand it in just a one-dimensional way, you can. Imagine that the full range of force a finger can produce is mapped from 0 to 100, and humans are sensitive to the degree they can adjust that by 1. Now imagine a weighted keyboard is responsive to the values between 10 and 60 -- that's 50 levels of sensitive gradation. An unweighted or semi-weighted keyboard is more like 25 to 35 -- merely 10 levels. Because we have so much less control, the software makes sure that the extremes are clipped -- you can't play as quietly or as loudly. Your dynamic expressiveness is severely limited. If you want to say "because physics", that's your "because physics".
You can measure this in MIDI outputs, actually. A good weighted keyboard will give you a wide range and an experienced pianist can consistently hit the same values without much noise. Whereas unweighted either gives you a much smaller range of values, or you can crank the output range up with software settings but discover that there's either a ton more signal noise because we don't have that fine control over our muscles, or else you discover that the intermediate MIDI values aren't even being used because the keyboard sensors don't support it (e.g. they only support 8 values).
> Pianists overwhelmingly prefer weighted keybeds out of habit, but more generalist keyboard players will often prefer a semi-weighted keybed for versatility. You can play gigs or sessions with either and you're the only one who's going to notice. Calling either choice wrong is just dogma.
That's false. Pianists don't prefer weighted out of habit, they prefer it because it's required for greater expressiveness, which classical/jazz requires.
The "more generalist" keyboard players you're referring to doing "gigs or sessions" are generlly not aiming for dynamic expressiveness -- they're part of a band or providing basic accompaniment to singers doing pop songs, and so forth. And that's fine -- unless it's Norah Jones-type music, you're not usually asking for much expressiveness from the piano in pop music. (She is much more jazz, after all.)
But that isn't "more generalist", it's pop. They're not practicing or performing Beethoven or Chopin, because it doesn't work except on a weighted keyboard. Nor are they doing jazz piano. You can't do it. Not well, anyways.
And you claim that "calling either choice wrong is just dogma", but that's wrong twice. First, I was very clear than there's nothing wrong with playing the synth. If you want to play synth music, I was clear that unweighted is great (you wouldn't even want weighted, actually). I specifically said weighted is necessary for classical and jazz. But second, it's not "dogma" that you need weighted for classical and jazz. It's just facts. It's "because physics", and the sensitivity of human physiology specifically. It's not dogma -- it's just reality. It's how the two instruments work.
Unweighted keyboards tend to have simple springs to return the keys to resting position, and more importantly, the cheapest instruments tend to only have note-ON;note-OFF characteristics due to being unable to sense any variation in how a note is played. These instruments playing all notes at the same volume is a natural consequence of inadequate sensors.
Returning to your sample values, MIDI 1 only directly supports 256 levels of volume, I think? This 8-bit level of variation is far lower than what any normal human sensory input can be expected to discern. MIDI 2, which was still very rare when last I paid heed, is a substantial improvement for potential expressivity. But even many years later, most consumer-grade instruments and playback devices only supported MIDI 1, sometimes with extensions such as GS or XG. The most expressive of the pro or semi-pro instruments that I've experienced have only seemed fully capable when using their internal proprietary enhancements; when outputting to a MIDI 1, the results were much less impressive.
As an aside, I've played only one piano whose keys felt as lightly weighted as my first semi-weighted keyboard and I found it a delight to use. Fully expressive, and less effort for the same effect as other pianos. I felt like I could play it for hours without tiring. By comparison, keys on all other pianos I've tried now feel quite heavy. I wish I could have afforded that one at the time. Sadly, memory of its make and model are long garbage collected.
I know I can play with high musicality on almost any keyboards with velocity, because I was blessed to have learned to use bad instruments. But, it doesn't compare to the depth of the sound generated by all the moving parts and interactions happening in a real piano. Not only the sounds, but also the sheer weight of the keys.
Most* keyboards/vsts are just triggering a (pitch-shifted, looped) sample at a given note and then doing that for n notes and that doing an additive sum.
That is definitely not what occurs in a piano though. There you have the 3-dimensionality of the physical world, like the way waves are traveling through distance and shape. When sounds' harmonics interact, resonant nodes in overtone sequences can trigger each other to resonance, which can trigger other resonances throughout the tone. Maybe you know the feeling of depressing the sustain/damper pedal while sitting in front of it and giving the instrument a smack (or holding down the keys you are not playing and doing it). Or running your nail or a pick over all the low notes with sustain.. like you are in a cave.
In midi/digital, there's the fact that dynamic is usually gonna be 8-bit. Just because midi did that and it made sense at the time, other keyboards and VSTs mostly follow suit. I'm surprised this gets generally passed over. Obviously there's more than 128 strengths of note in real life.
But all that said I think it's possible to learn keyboards/music theory/songs/playing on a non-weighted keyboard, but false to say that digital/non-weighted is equivalent to acoustic piano. But you only really need that for really dynamic music like Jazz, Classical, Instrumental et al. But it feels so very wrong to play that kind of music on bad keyboards.
* Roland V-Piano, and PianoTeq, as well as many I'm unaware of do in fact use physical/acoustic modeling as opposed to triggering samples, but it has not been predominant even among high-end digital instruments
