The musical instrument piano was borrowed into English from French piano around 1790. The French word piano is a clipped form of French pianoforte, borrowed from the Italian short name of the instrument. The Italian word pianoforte is short for “un cimbalo di cipresso di piano e forte”, meaning “a keyboard of cypress with soft and loud”. It was invented and given its unwieldy name by Paduan instrument maker Bartolomeo Cristofori around 1700. The key innovation made by the piano over its harpsichord predecessors was that pianists could control how loud a note was by how hard they pressed the keys.

Piano design changed drastically during their first 200 years of existence. Modern pianos, featuring 88 keys spanning seven octaves, typically differ only incrementally from their codified 1890 designs. Earlier pianos now go by the retronym fortepiano and had ranges that steadily increased from their initial four octaves to the contemporary seven. Any classical music that includes a piano was probably composed after its popularization in the 1740s. Piano wire has been so called since 1806.

The Italian word piano meaning “soft”, but also “flat” or “level”, descends from Latin plānus, meaning “level”. Plānus is also the ancestor of English plan and plain, both borrowings from the same French word (plain) in different centuries and circumstances. Looking at sibling languages, the English word that would have been used before it borrowed plain was probably flats.

The Italian word forte (superlative form fortissimo) meaning “loud”, but also “strong”, descends from Latin fortis, meaning “strong” or “steadfast”. Fortis is also the ancestor of English fort and forte, both borrowings from the same French word (fort) in different centuries and circumstances. Looking at sibling languages, the English word that would have been used before it borrowed fort was probably fastness. Notably, the English word forte was originally two different words, one borrowed from French fort, meaning “strength” and originally pronounced as a single syllable, and the other borrowed from Italian forte, meaning “loud” and originally pronounced as two syllables.