WITH HYPNOTIC, vibrating drumbeats dominating the skies, most people in Iloilo have been building up day-long stamina for a riotous weekend.

Yes, it's Dinagyang! A time of revelry and merrymaking that makes almost everybody forget tomorrow yet recall the historic past of a proud culture. A time to dance, drink, eat, laugh, shout and yell in the streets of Iloilo City as drums thunder and jolt the metropolis till next morning when all are already weary.

Dinagyang, which literally means ''to make merry,'' is a two-day citywide party held every fourth weekend of January to honor the Sto. Niño or the Child Jesus. Main attraction is the ati-ati contest where soot-covered dancers, presented as ati warriors, gyrate their bodies in choreographed steps as the drums rumble.

The colorful and exciting prancing of ati warriors is punctuated with shouts of ''Viva Señor Niño!'' and yells of ''Hala Bira!'' as they raise spears and shields.

The contest will be held on Sunday, the last of the two-day festival highlight.

The ati warriors, clad in meticulously crafted headdresses and costumes made of native materials, remind every Ilonggo of how their forebears celebrated with the original inhabitants of Panay.

Legends have it that the ''atiatihan'' (mimicking the ati dances) originated when the Malays celebrated the barter of Panay in the 12th century by painting themselves black to blend with the ati (Aetas).

The Aetas, the original inhabitants of the island, sold the lowlands to the Bornean datus who sought refuge in Panay after fleeing the tyrannical rule of Sultan Makatunao.

After the pact was sealed, an unprecedented merrymaking exploded, which prompted the Malays to paint their bodies with soot to ease insecurity among the natives.

To commemorate the barter, the Malays celebrated the atiatihan every year. It evolved to become a tradition in Aklan, Antique, Capiz and Iloilo.

When the Spaniards came, the pagan tradition blended with Christianity. In Kalibo, Aklan's capital, the atiatihan became a major feature of the town fiesta in honor of the Sto. Niño.

When an image of the Sto. Niño de Cebu was brought by an Augustinian priest in 1968, parishioners in the Parish of San Jose Placer welcomed it with the atitihan.

From then on, atitihan dances became a regular feature of the feast of the Sto. Niño every January. It came to be known as Iloilo Atitihan.

When the celebration became more riotous, the term ''Dinagyang'' was adopted in 1977 to distinguish the fiesta from Kalibo.

Commercialism benumbed the Dinagyang of its past and transformed it into a chaotic ritual marred by stabbing, shooting and fighting cases. But slowly, Dinagyang is reverting to its religious event rather than an advertising fair, according to Helen Camarista, assistant director of the Department of Tourism.

''Before, the Dinagyang was dictated by the caprice of commercialism. Now, it's religious spirit is slowly returning and commercialism has gone to the backstage,'' she said. Organizers hope to see Dinagyang become a truly religious fiesta.

''Although the business community will still be there as supporters, we want them to consider their support for Dinagyang as an obligation rather than as a commercial venture,'' she said.

To give more focus on the event's religious roots, organizers picked the theme ''Move towards Christ'' for this year's festivities.

A colorful fluvial procession will be held tomorrow at the Iloilo River while the Kasadyahan Festival, a competition of traditional dances and customs, will be held on Saturday.

To add color to the celebration, the 1999 Dinagyang Executive Committee introduced other activities, such as the first Iloilo Film Festival, the Marlboro Dinagyang Drag Race and the Iloilo Food Festival.

The five entries in the film festival--''Ang Babae sa Bintana'', ''Jose Rizal'', ''Kasal-kasalan (Sakalan)'', ''Hiwaga ng Panday'' and ''Sambahin ang Ngalan Mo''--are being shown in local theaters until Jan. 25.

The drag race features teams not only from Iloilo but also from Cebu, Cagayan de Oro City, Negros Occidental and Manila in a quarter-mile (402-meter) event, starting today until tomorrow at the so-called Centennial Bypass Road in Sta. Barbara town, 16 km west of Iloilo City.