Well, I got this from a Max interview in Down Beat, I think it was. Supposedly Max had one album left on his Atlantic contract, and he began to be, as they say, "advised" by the label to "consider" making an album of "familiar" music. Max says that he thought to himself, "Well, what could be more familiar than a program Negro Spirituals? EVERYBODY knows those", and went on ahead and recorded LEVAS, an album that finds the common ground between free jazz and gospel, replete with a non-hesitant, if you know what I man, choral group. The album was not a popular favorite.
Atlantic was not amused, and, after striking what was considered a "militant" profile throughout the 60s into the 70s, Max was dropped by Atlantic and apparently viewed as irrelevant by American record companies, since this was Max's last American release until Bruce Lundvall hooked him up with Columbia about 6 or 7 years later. Plenty of good, new stuff came out in Europe and Japan though!