"African language" declamation in music

I have been puzzling over some declamatory text incorporated in a piece
of music which my band (a British brass band) have been playing
recently. The question in my mind is whether it is an actual phrase or
sentence from a real language, or whether it has been "made up" as
sounding euphonious (in context).

The piece in question is entitled "Windows of the World", and the
relevant movement is entitled "Drums of Thunder". At one point some of
the players are required to declaim the following (and I shall
hyphenate it as on the copy):

"Fa-ya-kum-wambo kum-wambo nee-soomwa".

>>From my limited knowledge, it appears to me that this is not Swahili,
and perhaps not a Bantu language at all. The "kum" syllable is
reminiscent of the Arabic 2nd pers. plural, but equally clearly it
ain't Arabic.

Can anyone cast any light on this? My own suspicion is that the
syllables have been put together by the composer purely for purposes of
euphony, but I would be happy to be proved wrong.

Martin Taylor

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