RMAL was a very active un-moderated group where many very intelligent and instructive discussions/arguments regarding Afro-Latin influenced music took place on a regular basis.
Unfortunately, due to the fact that it was not moderated, it deteriorated over time as many off-topic posts were made which eventually lead to virtually all participants either quitting or moving to moderated groups such as Latin-Jazz.
Note: 2009/11/01 RMAL still has a few participants and, for some time, I have participated in very off-topic posts.
The following recommendations were created by various members of RMAL and I was lucky enough to be able to save their efforts for posterity before the group disintegrated:
Curtis Lanoue provided examples of 13th chords in Latin Music: