The Evolution of the Piano

Dulcimer

1500 BCE

http://leecagledulcimers.com/id62.html
(Exact date isn't specified)
The first piano instrument, Dulcimer, originated from Iran shortly after the birth of Christ. The Dulcimer is a thinner instrument with 3-5 strings and a fretted keyboard. It illustrate the basic principles of the piano but instead of mechanical hammers, this is played by strumming the strings with a small stick on the right hand while the left change the tune.

Virginal

Jan 11, 1511

https://www.britannica.com/art/virginal
http://www.thepianospace.com/tour/virginals.html
This product was first invented in 1511 by Sebastian Virdung that is a small harpsichord with right-angled keys to a single set of strings. It produces a louder tone than the clavichord but doesn't produce different dynamics. This instrument was also used in Shakespeare's time of the keyboard composers.

Harpsichord

Jan 1, 1550

https://www.britannica.com/art/harpsichord
The harpsichord came in the early 15th century around the period of Bach and Handel. Its shape and patterns are similar to our modern grand piano with the increase in tonal range from the spinet. Builders developed multiple keyboards with devices that enables one key to pluck several strings at once and stops. Although, this instrument is not capable of changing dynamics, not until they improved it again, moving towards the Modern Grand Piano.

Clavichord

Jan 1, 1730

http://www.ukpianos.co.uk/clavichord-history
https://www.britannica.com/art/clavichord
(Exact Date isn't specified.)
This product was invented around the 1400s. The case of this instrument is a rectangular shaped that is usually highly decorated, painted, and inlaid. The treble side contains a soundboard, bridge, wrest, and tuning pins. These clavichords are fretted, have the ability to create vibrato, and achieved different dynamics.

Spinet

Jan 1, 1800

http://www.infoplease.com/encyclopedia/entertainment/spinet.html
(Exact Date wasn't specified)

The spinet was created by the English in the late 17th century but it originated from Italy. Its mechanism is similar to the virginal, where you have to pluck the strings. Although, because of the wing shape, its longer strings increases the volume and the range up to 5 octaves.

Upright Piano

Jan 1, 1800

https://www.britannica.com/art/upright-piano
http://www.internetmeridian.com/piano/history/Grand_Piano.html
(Exact date isn't specified)
The Upright Piano uses a soundboard and strings that run vertically and perpendicularly to the keyboard. This was the first time the strings were extended behind the keyboard to the floor, which was designed by John Isaac Hawkins and Matthias Muller.

Square Grand Piano

Jan 1, 1845

http://squarepianos.com/square.html
(Exact date isn't specified)

The Square Piano originated from Germany where builders adapted Cristofori's piano-forte to the original shape of the Clavichord. The high tension of the shortest strings help new developments of the frame, which increased stability in tuning and extensions of the keyboard. Their small structure made it suitable for any room such as the ease to carry it from room to room.

Modern Grand Piano

Jan 1, 1900

http://pianonet.com/all-about-pianos/history-of-the-piano/
(Exact Date isn't specified)

The Modern Grand Piano have all the improvements from the previous pianos such as bigger musical range and depth, durability, stability, and richer tone from resonance. Modern building equipments such as glues, wood, wire, and process enables this piano to be most used.