South Africa's most famous jazz artists, Abdullah Ibrahim and Hugh Masekela, paid musical tribute to the struggle against apartheid in very different ways during the Capital City Jazz Festival at the Washington Convention Center Saturday afternoon. Ibrahim's septet evoked the dignity of South Africa's democratic activists with one of the most majestic jazz concerts here in some time. Masekela's octet conjured up the restless energy of South Africa's townships with the rollicking dance rhythms of African pop music.

Many jazz artists imitate and pay tribute to Duke Ellington, but the 51-year-old Ibrahim is one of the few whose compositions and arrangements have the same power and beauty.

His all-star septet, featuring Thelonious Monk's drummer Ben Riley and John Coltrane's heir Ricky Ford, boasted such a sure, full tone that it sounded like an ensemble twice as large. On "Dedication to Nelson Mandela," Ibrahim dryly delivered a poem over his own Monk-like piano solo; his Ekaya ensemble followed with a lushly harmonized swing coda.

Masekela has largely abandoned the American jazz of his earlier career for an African-pop sound that mixes Nigeria's Afrobeat with South Africa's Zulu music. The 46-year-old Masekela punctuated the rolling rhythms with piercing trumpet and fluegelhorn solos, but he also proved a surprisingly strong baritone singer. He led his Kalahari ensemble through extended call-and-response songs that had the crowd dancing in the aisles. On protest dance numbers like "Bring Back Nelson Mandela," John Selowane's lyrical guitar solos and echoing vocals were an added treat.