A Korg stage piano is manufactured by Korg which was founded in 1962 in Japan, by two Japanese men with backgrounds in the nightclub industry and an accordionist who played at on of the nightclubs. In 1963 the first product was rolled out and was a success, so it successor was launched 3 years later. Korg has released a whole host of electronic music products and a number of great stage pianos.
SP200 Korg Stage Piano
In 2002 the SP200 Korg stage piano was launched at a trade show and well received. It is a lightweight 88 key stage piano, but retains a deep defined natural sound. It reproduces the touch of a modern acoustic piano. It is aimed at student players as it has a convenient built in metronome and headphone output socket to help students practice.
The New SP250 Korg Stage Piano

The SP250 Korg stage piano is the first in the Korg series to feature the new ‘RH3′ real hammer technology. This gives it an authentic piano feel. It has 60 note of polyphony and has an onboard speaker system with two 11W speakers. It is great for portability too as it only weights 19kg. The sound is bright and strong and has 30 built in sounds, plus a whole host of extra effects.
It also comes with a stand and pedal included, so the total package is great value for money. Two headphone jacks make this ideal for a student/teacher session without disturbing others.
SP500 Korg Stage Piano
The product has been discontinued in the UK, so look at the Korg SP250 instead.
For an alternative to a Korg try an M-audio stage piano