ABSOLUTE MINIMUM : Digital 61-key touch-sensitive keyboard.
61 keys are enough to start. WARNING: you can’t play advanced classical music on 61 keys OR get much bass sound, so 88 keys (full size) keyboard is better for that. Obviously 61 keys is an easier size to carry around, if that’s a consideration.
Touch sensitive = when you play harder, the notes sound louder.
Necessary to play piano. Piano is short for pianoforte (softloud in Italian) so the great new technology that the piano introduced back in the 1700’s was a keyboard instrument that could be played soft or loud, according to the touch. So piano music is usually expressive music that needs this capability.
64 NOTE POLYPHONY (MORE IS BETTER)
WEIGHTED KEYS? Optional at first.
Unweighted 61-key keyboards are not designed for use by classical (or a lot of jazz) pianists; they’re designed for use as synthesizers. These kind of keyboards are great for pop or praise music.
FOOTSWITCH OR PEDAL: Go ahead and get it now, you’re going to need it soon enough.
Necessary, but not always included. Make sure you’ve got it.
DO YOU LIKE THE WAY IT SOUNDS AND FEELS? THIS IS REALLY IMPORTANT.
Are very expensive. They are absolutely the best to play classical music, but they need tuned and maintained, and are absolutely NOT portable. And they are always loud, (no option of plugging in headphones).
Don’t ever get an old piano that someone wants to just get rid of. It is very heavy, piano technicians are very expensive, and you might be ruined for life if you play it untuned.