How many keys are sufficient?

[ev1lchris]

I'm restricted by space and budget so I don't have an 88 key midi controller.

The one I have with the most keys are a 71 key keyboard and 49 keys.

Do people really need all 88 keys for most purposes?

[BONES]

No. I find three octaves is plenty for playing one-handed. You might need more if you are planning on playing two-handed but you could always get two smaller keyboards, one for each hand, and stack them. If you are not going to be playing a lot of chords, you might even get away with just two octaves (25 keys).

You could also try mini-keys. They used to be rubbish but in the past few years they've improved a lot. Arturia's KeyStep is as good to play as any full-size unweighted keyboard.

[PieBerger]

If you're already doubting the need for 88 keys, you probably don't need 88 keys

[ramseysounds]

Arturia's KeyStep is as good to play as any full-size unweighted keyboard.

Its not though is it? If you’ve spent your whole life playing on full size keys, to then change to mini keys is a huge change to your hands and fingers.

@op I suggest only you really know what’s right for you

[cryophonik]

If you're already doubting the need for 88 keys, you probably don't need 88 keys

Agreed.

OP, are you, or do you plan to be, a pianist? If not and you're only using a keyboard to input notes for synth parts, then 76 keys is probably more than adequate. I am a formerly trained pianist and I rarely find myself needing more than 61 keys in a MIDI controller. I have a few other synths/controllers that have 25 and 37 keys, which overall tend to work fine for simple synth/bass lines. But, I personally find 61 keys to be the best compromise for two-handed playing vs. space consumption. YMMV, of course.

[kritikon]

Same as said above. Depends on how/what you're playing. Personally I'm not a piano player & never was. Can play a bit though & mostly making electronic beat-based music, techno, acid, straying into dub and occasionally some ambienty kinda stuff with soft beats, so I almost never play 2 handed. As Bones said - 3 octaves is fine (for me & my style). TBH I don't even need or want aftertouch - can't remember the last time I used it. If you make music anything like above, then odds are you also don't need a large keyboard. In fact for me, the best keyboard I have for diddling about on is an old Yamaha DX100 - tiny wee thing with the crappiest keyboard you ever will see, no velocity, no aftertouch and minikeys. But takes up little space, lightweight so I can even sit it on my knee if I want and I can bang out chords that don't stretch the amateur fingers. Real musicians likely detest it. I've used it on and off for 30 years and it hasn't stopped me making the kind of music I want. I've had big keyboards and TBH didn't like them much apart from looking good in the studio... i.e. a waste of space.

[BBFG#]

It really is a personal preference for everyone to what they're triggering and what's comfortable to do that.
I've had everything from mini-one-octave to full size 88's (although I don't believe I've ever had a 71 key). What's most comfortable for me that anyone makes is the 73 key C-C keyboard for range, but for key weight it pretty much has to be the 88. And even with the 73 key I do find I often want just five more keys for the range of C-F. (78 keys in that range that no one makes AFAIK.)
Something else to consider is whether you're using samplers or not and to remember that many libraries map trigger switches to the lower register. So having to balance between triggering those while playing will increase the range you need to do so.
Originally, the research done on this came up with 61 keys as the most common range to complete the tasks, but this seems short-sighted to me now. And the biggest waste of money to me has been the 25key - 2 octave full size keys. Even the market shows that most of us consider 3 octave to be the real minimum.
One more thing to remember is the ability to split and/or zone/layer your plugins... which means your 88 key can actually be separate synths consolidated in a single space.

Note though that I am a keyboard player whose setup is now two 88s and a single 13 key for pedal. And the foot pedal is smaller than I often actually need by at least three notes.

[zerocrossing]

For me, I find 61 keys to be a sweet spot, but I'll settle for 49 for some things, like my Rise 49. If they ever do a Rise 61, I'll definitely upgrade, but it doesn't seem to be a future possibility.

[Aloysius]

C3 = ONE

[BONES]

Its not though is it? If you’ve spent your whole life playing on full size keys, to then change to mini keys is a huge change to your hands and fingers.

After 30 years of playing full size keys, I had pretty much zero trouble adapting at all. I definitely thought I would but it didn't eventuate. I can even play a full-size keyboard with one hand and mini keys with the other and it's OK. I'm a shit keyboard player at the best of times, maybe that helps.

What I did discover is that the shorter length of mini-keys is as much of a problem as their narrower width, in that the longer keys on a Minilogue or Monologue are so much more satisfying to play than the shorter keys on most mini keyboards. But it's all doable and I adapted very easily.

[ghettosynth]

C3 = ONE

Sounds like an Apple product. A perfect match for this:

[FranklyFlawless]

You only need 88 keys if you are playing or creating piano repertoire with two hands. If you write song parts one at a time, you can get away with far less.

[xbow]

Similar to what others have said, I find 25 keys to little, 37 ok for one handed parts (but I hate mini keys). I was surprised to find how well the 49 keys of the Hydrasynth work for two hands (and the form factor is very convenient). That said, 61 keys are still worth it if you have the space. 73 keys is my favorite size even if I rarely need the full range.

[kvotchin]

61 works well for me, but honestly, 49 would probably be fine too.

[BertKoor]

Do people really need all 88 keys for most purposes?

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

37 is good for one hand playing, for plenty people. I have a 48 keys controller: too small for semi-serious 2-hand playing. 60 or 66. 72 maybe.

It's all on the market, so plenty choice