Pianos are one of the loveliest forms of musical instrument today, though they vary greatly since their creation in the early 1700's by Bartolomeo Cristofori, widely held to be the inventor of the pianoforte, which gradually evolved into the piano. Pianos themselves have gone through a gradual evolution, and the development of the modern piano truly began during the industrial revolution, with access to technology and material that offered pianists a more sustained, powerful piano sound.
Today, pianos come in a couple different forms: the 'upright' piano and the 'grand' piano. The grand piano is placed horizontally and the strings extend away from the keyboard. The grad piano is often large and longer than upright pianos, giving them a better sound and greater resonance.
Grand piano sizes range from about one to three meters long, though they can be smaller; the smaller grand pianos are known as 'baby' grands, which are more often used in homes and areas where space and price is a consideration. Concert and boudoir grand pianos can generally be found in larger spaces like concert halls, lobbies and even larger homes.
Upright pianos are placed vertically (thus their other name, vertical pianos), making them smaller and shorter than grand pianos. Upright pianos are generally more compact and though they were once inferior to grand pianos, technology has brought them to a level where the differences aren't important to the average consumer.
Upright pianos are generally less expensive than grand pianos and are found in a multitude of locations. Though upright pianos have become nearly as sophisticated as grand pianos, the horizontal layout of a grand piano allows for more sensitive piano action. Grand pianos also have a special lever that allows pianists to play repeated notes, trills and staccato with more speed and control than an upright, or vertical, piano.
Versions of pianos can also be found in other offshoots like digital keyboards, which use digital technology to reproduce the sound of a piano. Though progress is being made with regards to quality of sound, digital keyboards can't currently math the tonal quality of acoustic pianos. Another offshoot is the prepared piano, whereby the musician places 'preparations' (objects) between or on the strings, dampers or hammers to change the sound. This is a relatively recent development but has been used musicians across the board.