How many keys are sufficient?

[cryophonik]

Some: yes. I have a friend prof piano player, he swears by no less than 88 keys.

This must be your friend, then...

[Fornicras]

For the desktop mini controller I think 32 keys is the best, for the big controller, I think it should be minimum 61. That's what I'm comfortable with at least.

[systemfreak]

As someone who has two extremes (a fully weighted-key 88 key digital piano, and a 30-something slim-key midi keyboard)
I would argue the sweetspot is somewhere between 49 and 61 keys.
You (meaning “I”) don’t generally need the upper or lower 2 octaves on any keyboard.
If you’re not a piano player, you’ll rarely if ever touch them.

My next keyboard purchase will probably be a 61key full sized key midi keyboard

[DocAtlas]

Some: yes. I have a friend prof piano player, he swears by no less than 88 keys.

This must be your friend, then...

Where is middle C?

Still a bit more manageble than the 500-seat keyboard in this movie: https://www.moriareviews.com/fantasy/50 ... t-1953.htm

Seriously, to address BertKoor's comment, if you're a pianist or planning to become one, then you might want to consider 88 keys. But if you aren't, the two you have are probably plenty, especially if space is an issue. I consider myself more of an organist than a pianist, so my preferance is usually for multiple 61-key manuals. But I do have an 88-key controller, and one of my synths has 76 keys. If you only occasionally play in the extreme ranges, stick with what you have, and transpose up or down an octave when needed.

[YnJ]

I have yet to come across a piano piece which uses all 88 keys, I'm sure some composer somewhere at some point in time wrote a piece using both the lowest and highest note, 71 keys will probably do fine though

As for synths, I got a 25 key controller for use as a desktop controller, the size is nice, I hardly ever use it as it 's way to limiting for playing though. For a main controller 49 keys can be a bit limiting if you use both hands so I would recommend 61 keys

[BBFG#]

Who makes a 71 key?
All I find are either 73 or 76.

[YnJ]

I don't know, I wrote 71 keys as that was what OP wrote he had

[vitocorleone123]

37 keys is good for me for one or two handed playing. No space for anything bigger. Had 25 keys and it was never enough.

37 is minimum. 49 is comfortable for non pianists, 61 is the sweet spot for keys players. 88 for professionals.

[kritikon]

I only have 10 fingers so really, 10 keys would be enough for me...and I can't actually play with 10 fingers anyway. I can probably get away with 3 keys, maybe 4 so I have a root note for when I get adventurous.

[owenpoe]

I went from an 88 key to realizing I never used all the keys, then to a 49 key, and realizing I needed more keys. I've finally landed on a 61 key and am very happy with it, never felt the need for more.

[TurtleCrossing]

To echo what others have said, I've also found 49 keys to be more than enough as a non-pianist

[reason4]

88 keys is great if you're going to play live and/or need to create splits to play different parts/programs/patches simultaneously. But in the studio, I find 49 or 61 keys to be plenty. I use a KK S49 (49 keys) as my main driver for VSTs, and also a Minilab 3 (25 keys) which is great for jotting down ideas (it's always within reach on the desk) but also for controlling sounds via MIDI cc thanks to the encoders and faders.

[dlandis]

For most things, 61 keys are sufficient. I do own a weighted 88 key controller (in addition to a 61 key semi-weighted controller, a WX5, TrapKat drum controller, Maschine, and two Seaboards and TouchBlock for MPE.)

It really depends on what you do, how you write, what your major instrument is, and probably several other factors. I bought the 88 key controller to replace my dead Kurzweil MidiBoard (lightning took it out before I could turn it off and unplug it. I'm kind of thankful that, besides an aged modem, that's all I lost.) I have actually used most of the keys on it at some time or another in compositions including the very lowest A and up to the very highest F#. I do prefer to play my parts as opposed to "cursoring" them in, though I wouldn't argue for my classical chops on piano being worth that much (I'm more about jazz, but the low A was in a piece that was more classically oriented, as was the F#, come to think of it.)

Perhaps of more importance than the number of keys, however, is the weighting? YMMV, but I'd really rather not play piano parts on a semi- or unweighted keyboard. It feels very unnatural to me and I feel like I can't really dig in. Conversely, playing organ parts on a fully weighted keyboard feels very odd. Playing soloistic wind parts is strange if I don't play it on a WX5 (I am primarily a saxophonist.)

Again, FWIW.

[vurt]

i only need one to blow your mind!

[El°HYM]

i only need one to blow your mind!

All hail Lord Vurt.