In this year of socially concerned pop musicians, performers have taken two approaches to world problems. Some have taken the charitable approach, using their celebrity to raise money for the world's unfortunates. Others have taken the political approach, using their talents to raise awareness about the conditions that create such problems.

Kashif, Brooklyn's 26-year-old rhythm and blues hit-maker, is doing both. Previously known as a studio wiz and a love-song crooner, Kashif followed up his verse on the all-star antiapartheid "Sun City" with his own composition, "Botha, Botha (Apartheid Song)," on his new album "Condition of the Heart."

"I don't know why I didn't do anything like this earlier," says Kashif, who performs at the Warner Theatre tonight in a concert that will benefit the Easter Seal Society for Disabled Children and Adults. "I guess it's just a natural outgrowth of growing up and becoming more mature. I wanted to exercise these different muscles as an artist, and I figured there was no better time than now.

"Artists and entertainers are just now learning their power to bring about nonviolent social change," he says. "We have the ability to get our listeners emotional and stimulated, and we might as well use it for something positive."

"Botha Botha (Apartheid Song)" opens with Kashif's typically inventive work -- synthesized harpsichords, church bells, harps and tribal drums, reminiscent of Stevie Wonder's recent music. The verses argue: "Multinational corporations sit and agree that they lose all profits if they set South Africa free." The chorus offers this bouncy sing-along: "Botha Botha Botha, we can't dance because you're standing on our feet."

"I have a couple of South African friends," Kashif notes, "the jazz pianist Dollar Brand and the Harlem record-store owner Sekulu, and they kept me informed about the situation there. A lot of people, though, aren't that well informed about South Africa, and educating them can be my contribution to the cause."

Another of Kashif's pet projects is the Black Adoption Awareness Campaign, for which he does public-service announcements to get out the word that there are many black children who need adoptive parents. Kashif himself was an orphan who was shuttled from one foster home to another.

"I do it," he says, "so other kids won't have to go through what I went through: not having parents, not having a stable home, just nomading."

Kashif, who took his stage name from the Arabic word for inventor, got through his uncertain childhood because "music was my best friend," he says. "It was my refuge from all the negative aspects of being an orphan from birth. One reason I excelled at music is I was doing it all the time; I had nothing else to do."

When he was 15, a classmate recommended him to her father, the manager of the disco band B.T. Express. "Two days after graduation I auditioned," Kashif remembers. "The next day I was hired. The next day we rehearsed, and the day after that we left for a worldwide tour that began in Thailand."

After 3 1/2 years with B.T. Express and a tour with Stephanie Mills, Kashif was hired to coproduce Evelyn King's 1981 album, "I'm in Love." He wrote the title track, which became a smash single. He had another hit with King in 1982 with the hit single "Love Come Down." That led to offers to work with Howard Johnson, George Benson and Melba Moore, as well as to his own contract as a singer.

"I didn't mind staying behind the scenes for a while once we had a couple hits," Kashif maintains. "I was getting an education that would prove invaluable when I went to do my own album. I was also getting a name that would help me with programmers, disc jockeys and fans. When my first album came out, I wasn't a stranger, I didn't get those 'new artist blues.' In fact, I became the first black artist to ever have four singles released off his first album."

His self-titled 1983 debut album not only yielded a No. 1 R&B single, "I Just Gotta Have You (Lover Turn Me On)," but also established him as one of the experts in the new musical technology. He layered electronic keyboards and electronic percussion in a way that added a state-of-the-art luster to his Motownish pop-soul without overwhelming it.

"All that technology does is help us realize our musical goals," he says. "It's a tool -- nothing more, nothing less. It gives you a lot more flexibility at your fingertips. When you think of an idea, you can go through a lot of variations immediately. Instead of spending hours or days trying to get a great drum sound, you push a button and you have a great drum sound.

"People are always going to object to new machines. It's just like when cars came along; all the horse-and-buggy owners got all upset. The trick is to have the technology serve the song, not the other way around. You have to make sure the melody and the story in the song are there first and not rely on the machines to make it work."