Update Winter 2016: Check out my recommendation for the best digital stage piano under $2,000.
Unlike voice or clarinet students, the piano student is faced with a bewildering array of instrument choices. Acoustic or electronic? If acoustic, grand or upright? Which manufacturer is best? If electronic, how many keys? Weighted or nonweighted action? How many sounds?
The decision to invest in an acoustic piano, weighted-action digital piano or non-weighted-action synthesizer needs to take into account your playing level, styles of music you want to play, your overall musical goals, and whether you’re a hobbyist or aspiring professional. (Weighted-action means that the keys, when played, have resistance like an acoustic piano.)
Your Playing Level
A beginner can potentially get by with a cheap, non-weighted action synthesizer for a month or two, as long as it has full-size keys. But the technique necessary for becoming a truly proficient piano player cannot be learned on a synthesizer. Soon enough it will be necessary to invest in a digital or acoustic piano.
The Styles You Want to Play
Different styles of music use different instruments. Anyone aspiring to play classical music should be practicing on a weighted-action digital piano from the beginning, or even better, an acoustic piano. (Digital pianos, despite how advanced they’ve become, are still no match for a high-quality acoustic piano, and probably never will be.) Similarly, anyone aspiring to play jazz should be playing on a high-quality digital or acoustic piano as soon as possible. Only if you are extremely sure that you will only ever want to play popular styles of music usually performed on electronic instruments can you realistically get by with a cheaper, non-weighted action electronic keyboard.
Your Musical Goals
Also consider your musical goals. If they include performing for others, you will want to be able to play any instrument you’re presented with. (Unlike most instrumentalists, who can easily carry their instrument, keyboard players must get used to playing a variety of individual instruments, unless you always plan to have a roadie with you.) To be able to do this, you will need to learn on a weighted-action keyboard like a digital or acoustic piano. Because of the technique required to be a good player, it is much harder to make the transition from a nonweighted-action synthesizer to a digital or acoustic piano than vice versa.
Hobbyist or Aspiring Professional?
Finally, consider how good a player you aspire to be. Of course, the higher you aspire, the better you are likely to become. If you are shooting high, it is absolutely essential that you spend most of your practice time on an acoustic piano. Only a high-quality piano offers the sensitivity and resonance that is needed for skillfully playing the greatest keyboard music.
In Part Two, I’ll offer my specific recommendations on choosing an instrument, particularly for someone making their first purchase.