The instrument you heard is actually called a "fortepiano." In the history of keyboard instruments it stands between the harpsichord and the modern piano (short for "pianoforte"). It has hammers (like a piano), instead of plucking strings (like a harpsichord), but lacks the steel frame and wide octave and volume range and long sustains of a piano. But, it's quick and responsive and is favored by period performance specialists who want to recreate the experience of early 19th century music.
I think you will enjoy the fortepiano recordings of Melvyn Tan, who recorded several Mozart and Beethoven concertos with Roger Norrington for EMI (now Virgin Arkiv) in the '80's. I heard them perform together in NY then and was quite impressed.