The gravitational centre is the Parque do Povo in the city centre, a purpose-built festival ground that locals call the headquarters of forro. Bonfires, quadrilha square-dance troupes in ruffled costume, corn in every form the northeastern kitchen has invented - the June celebrations honour Saint John with a repertoire that is older than the city itself and belongs to the whole Brazilian Northeast. What Campina Grande did was industrialise it. Stages spread across neighbourhoods, a month-long programme organised by the municipality, and enough visitors to reorder the local economy for a quarter of the year. The rest of the calendar is not empty either - Micarande in April, the Winter Festival in August, New Year's Eve on the Acude Velho - but June is the month the city was built for.

Long before the stages, this was a place where people stopped walking. Campina Grande sits at 560 metres in the agreste, the transitional belt between Paraiba's humid coast and the semi-arid sertao beyond, on the natural route between the two. Tropeiros - travelling merchants moving meat, cotton cloth and corn flour between the highlands and the sea - rested here in both directions. The conventional founding date is 1 December 1697, credited to Captain Teodosio de Oliveira Ledo, who arrived with a group of Arius people to settle and farm the land. Some historians dispute that version, arguing a settlement already stood here and already carried the name when Ledo turned up. The geography favours the sceptics: a place this well positioned rarely waits to be discovered.

The shacks the Arius built became the settlement's first street. It was later called Rua do Oriente, the Street of the East, and survives today as Rua Vila Nova da Rainha. On 6 April 1790 the town was formally renamed Vila Nova da Rainha, New Village of the Queen, and given a council and a notary's office. Officials used the new name; everyone else went on saying Campina Grande, and the everyday name eventually won. Growth came from cotton, which the regional industry preferred to ship through here. In 1829 work began on a dam across the Piabas stream, creating the lake still known as the Acude Velho - the old reservoir - which had been the village's original front yard. By 1852 the population had reached 17,900. Four years later an epidemic killed nearly 1,550 people, more bodies than the churches had ground to bury them in.

City status arrived on 11 October 1864, when Campina Grande amounted to three plazas, four streets and about three hundred houses. Then the railway reached it, and cotton turned the place inside out. By the early twentieth century the city was known as the Brazilian Liverpool, a nickname earned by the plantations and the factories and the sheer volume of fibre moving through its warehouses. Cotton money built the elegant municipal building that went up beside the cathedral in 1877 and the streets of fine houses that followed. Cotton money also made Campina Grande the economic rival of Areia, the older city that had dominated Paraiba's interior. When the cotton economy eventually faded, the warehouses stayed and the habit of trading stayed with them.

In 1967 the university here obtained support to buy a computer for 500,000 US dollars - the first in northeastern Brazil. It was an improbable purchase for a semi-arid interior city, and it turned out to be the beginning of something. The institution grew into the Federal University of Campina Grande, and around it accumulated the software firms and research groups that gave the city its second nickname. In April 2001 Newsweek picked nine cities worldwide as representing a new vision for technology. Campina Grande was the only one in Latin America. The Koppen classification here is As, a dry-summer tropical savanna sitting right on the boundary with hot semi-arid - the kind of climate that historically punished agricultural economies. Campina Grande's answer was to stop depending on rain.