There had been numerous attempts to manufacturer a piano that was both portable and sounded like the acoustic grand model.
Benjamin Miessner had been working on pickup and amplification techniques since the 1930s, and discovered that capturing the harmonic information and nuances of sound was difficult and changed as pickup positions and configurations were altered. Yamaha had been working on pickup technology since
World War II, and took advantage of Japanese culture at the time, which permitted research information to be exchanged between companies without threat of intellectual property lawsuits, as in the US. They used this knowledge to create a series of robust piezo-electric pickups, and combined it with their experience in manufacturing acoustic pianos to make an electric instrument. The CP-70 was first manufactured in 1976, and cost $4,000. According to
Toto's
David Paich, Yamaha invited a group of pianists in
Los Angeles to test the instrument before manufacturing. After playing, they were "just freaking out over it". The first model had problems with tuning, and an upgraded version, the CP-70B, was introduced at the
NAMM Show in 1978, along with the CP-80, which featured a full 88-note keyboard. It also introduced an
effects loop. The CP-70D and CP-80D models added a
graphic equaliser. The final models to be released were the
MIDI equipped CP-70M and CP-80M, which were released at the end of 1985. ==Maintenance==