African pop music welcomed in US. Some sounds, however, challenge Western ear

WHAT'S happening in African pop music? The New York International Festival of the Arts answered that question recently with a resounding ``Plenty!'' in two exciting concerts by four African groups: Youssou Ndour and his band, Salif Keita's group, percussionist Dou Dou Ndiaye Rose, and Les Amazones de Guin'ee - an all-female ensemble consisting entirely of African policewomen.

Youssou Ndour is Senegal's most famous pop singer, who achieved a certain degree of international fame in 1986 and '87 as the opening act for British rock singer Peter Gabriel's world tour. In Senegal, Ndour performs almost every day in stadiums, clubs, and in the public schools. His music is a kind of Senegalese rock called mbalax, and at his double-bill concert at the Beacon Theater here he showed that he is leaning more and more toward crossover into American pop and soul music - although he sings only in his native tongue, Wolof.

To say that Ndour's concert was captivating is an understatement. The exotic sound of his Islamic style of singing and his bell-like tenor voice, coupled with the complex and syncopated backup from his band and the magical sounds from a ``talking drum'' (a small narrow drum, squeezed under the arm to change tones and played with both the fingers and a small stick), made for a thrilling alternative to American pop bands.

The lanky, loose-jointed Ndour, with cap and multicolored shirt, never stopped moving to the music, and at certain prearranged but unexpected moments he and his band members would make a sudden turn in perfect unison, eliciting shrieks from the uninhibited, largely African audience, who later rushed to the stage, throwing money at the performers. Youssou Ndour has a new album coming out in early fall on Virgin, produced by Peter Gabriel.

On the same bill was Salif Keita, a singer from Mali, who has just released an album, ``Soro,'' on Island Records. A lower-key performer than Ndour, Keita, dressed in a baggy pale orange shirt and pants and purple sneakers, was conversational, offhand, humorous, childlike, and charming. His music also reflects a variety of international influences - his backup included African percussion, as well as synthesizers, rock guitars, and a jazz-influenced horn section. His female sidekick, Jenny, a fine singer and dancer, was featured as prominently as Keita himself. In one of the best parts of the show, he and his lead guitarist waged battle together, the former expertly imitating every nuance of Keita's voice, and needling him with aggressive thrusts of his guitar, to which Keita responded by yanking his hair!

The second program opened with the wonderful Amazones de Guin'ee. These 15 women have been together since 1961, and are a phenomenon in the sense that they have broken down musical barriers for all African women, who traditionally have not been allowed to play drums. Les Amazones, however, sported not only African drums, but timbales (Latin kettledrums) and a rock drum kit. In addition, there were three saxophonists, three singers, several guitarists, and a muscular, high-spirited dancer.

Les Amazones de Guin'ee sang rhythmic songs in French. Their music, like Salif's, is both listenable and danceable. They varied their program by breaking up into smaller groups, and featuring solos by one of the guitarists and by their energetic timbale player, who also did a dance that brought the house down. The sound of the saxophones is a trademark of this kind of music - it's raw and simple, and, to our ears, it sounds a little out of tune until you get used to it.

Percussion, of course, is central to African music. Dou Dou Ndiaye Rose is the master drummer of Senegal. He leads a spectacular percussion orchestra that has toured widely in Europe and Japan. He, like Les Amazones, has broken down prejudices against women by using many of his daughters and daughters-in-law in his orchestra.

The 32 drummers, who also danced and sang, put on a show that was rich in variety, both aurally and visually. Sometimes they would dance as they played, and the women would punctuate the drum rhythms with cries and shouts. Seeing that many people on stage, dressed in ever-changing colorful costumes, playing their drums with such energy and expertise, was truly exhilarating.