Origins
The word 'concert' has an etymology that embodies one of the most striking semantic reversals in the history of European languages. Its modern meaning — a harmonious public performance of music — descends from a Latin word that meant almost exactly the opposite: to fight, to contend, to dispute.
The Latin verb 'concertāre' is a compound of 'con-' (together) and 'certāre' (to strive, to contend), itself a frequentative form of 'cernere' (to sift, to decide, to distinguish). In classical Latin, 'concertāre' described competitive striving — arguing a point, disputing in court, contending in a match. There was nothing harmonious about it.
The transformation occurred in Italian during the Renaissance. The verb 'concertare' began to shift from 'to contend' toward 'to work things out together' and then 'to arrange, to agree.' The logic of the shift may have been that people who debate a matter vigorously eventually reach resolution and agreement. By the early sixteenth century, Italian 'concerto' had come to mean 'agreement' or 'harmony,' and then, by natural extension, a musical performance in which multiple players coordinated their efforts — played in concert.
Development
The noun entered French as 'concert' in the mid-sixteenth century and from French passed into English by the 1580s. In English, the word carried both its abstract sense ('in concert with' meaning 'in agreement with') and its specifically musical sense (a public performance). The musical sense gradually became dominant, though the abstract meaning survives in phrases like 'acting in concert' and in the verb 'to concert a plan.'
The related word 'concerto' was borrowed separately into English directly from Italian in the early eighteenth century, specifically to denote the musical form in which a solo instrument is featured against an orchestral accompaniment. Thus English has both 'concert' (from French, the general performance) and 'concerto' (from Italian, the specific musical form) — cousins from the same Italian source.
The verb 'disconcert,' meaning to unsettle or disturb, preserves the older adversarial sense more faithfully than 'concert' itself. To disconcert someone is to throw them out of harmony, to disrupt their composure — essentially to undo the agreement or arrangement that 'concert' implies.
Latin Roots
The Latin root 'certāre' (to strive) also gave English several other words through various routes. 'Certain' comes from Latin 'certus' (determined, resolved), the past participle of 'cernere.' 'Certify' means literally 'to make certain.' The connection between certainty and striving lies in the original meaning of 'cernere': to sift, to separate, to distinguish — from which come both the idea of resolving a matter (certainty) and the idea of competing to resolve it (contest).
The history of public concerts as musical events is relatively recent. In the medieval and Renaissance periods, music was performed in churches, courts, and private chambers, not for paying audiences. The first public concerts for which admission was charged emerged in London in the 1670s — the series organized by John Banister, a former court violinist, in his home near the Temple. By the early eighteenth century, public concert series had become established institutions across European cities.
The word 'concert' thus completed a remarkable three-stage journey: from Latin strife to Italian harmony to the quintessentially modern institution of the public musical performance. In every stage, the core idea of people coming together persists — first to fight, then to agree, finally to make music.