Across North Africa, small groups dominated by descendants of slaves brought from the Sahel preserve musical traditions, with ritual and medical functions, usually called Gnawa in Morocco, Diwan in Algeria, and Stambeli in Tunisia. Aguadé's Die Lieder der Gnawa aus Meknes provides the lyrics of an extensive corpus of Gnawa songs from Meknes in northern Morocco. These songs are primarily in Arabic, but characteristically include a number of words with no plausible Arabic or Berber source, presumed to derive from languages of the Sahel. Their identification, however, is generally difficult, although Aguadé ventures a few suggestions drawn from Hausa. Anyone can comb dictionaries for sound-alikes, but similar forms may be found across unrelated languages of the Sahel with very different meanings. It would be much easier if the meanings were certain, but the singers do not necessarily know the meaning of such words, and the context often hardly narrows it down. Nevertheless, some cases can be identified more confidently than others.
Aguadé's song number 88, Lalla l-Batul "Lady Virgin" (pp. 128-129), is dedicated to a female genie whose song cycle corresponds to the colour yellow. Its refrain (accounting for 5 out of its 8 lines) is a lalla l-batul, saysay "Oh Lady Virgin, saysay". The word saysay has no meaning in Arabic or in Berber. In Bambara, however, sáyi means "yellow"; the refrain would then be "Oh Lady Virgin, yellow, yellow".
In his song number 90 (pp. 130-132), the refrain is fufu dənba ya sidi "fufu dənba, oh master" (repeated 14 times, including the opening line of the song). Bambara dénba means "mother". The first verse after the initial refrain is ma bɣatək kda ya sidi "she didn't want you like that, oh master"; no feminine singular subject to which this could refer appears anywhere in the Arabic text of the song, but the Bambara interpretation allows this line to be better understood. I'd like to relate the preceding fufu to Bambara fò "greet" and/or fɔ́ "say, speak" - "greet Mother" would seem contextually appropriate - but I can't quite see how the grammar would hang together.
Addendum: In song 5, Sidi Gangafu "Mr. Gangafu", almost every couplet ends in Bambaṛa or shortened ya Mbaṛa, so a Bambara etymology seems worth considering (although an allusion to Hausa is also found). As Aguadé notes, Ganga is simply a kind of drum used by the Gnawa, whose name is shared across most of the Sahel, so one would expect this name to mean something like "drum-player" or "drum-maker". In fact, Gangafu can readily be interpreted as Bambara gàngan-fɔ̀ "play the ganga-drum". "Drum-player" should properly be something like gàngan-fɔ̀-la, but it doesn't seem like much of a stretch to suppose that the Bambara used by slaves among themselves would have had some non-standard features, given that for many of them it would have been a second language to begin with.