This collection of documents refers to my research, in which I led a initial clue published in a paper about the provenance of a collection of 6 Candomblé chants that would be recorded in Salvador in 1937, by the singer Olga Praguer Coelho, using an Edison's Phonograph requested by Mário de Andrade to the Berliner Phonogramm-Archiv. These recordings are, today, under custody of the Ethnologisches Museum of the Staatliche Museen zu Berlin, soon to be transferred to the Humboldt Forum. Despite the fact that this information is, today, considered the accepted hypothesis for the provenance of this recordings, many times replicated as source data in various papers, my research found no possible connection between what was published and the facts that I could check until now; which makes me think that the initial clue is wrong. Up to this date, I still could not find any confirmation about who/how/where the phonograms were collected, and if you know anything about this, I would be glad to hear from you, as my research will continue on this matter. All the references I had access can be found below, related especially to the II Congresso Afro-Brasileiro [2nd Afro-Brazilian Congress] in Salvador - which I believe it would be the most likely event for these recordings to have taken place in the 1937's Salvador, as well as personal letters exchanged between some of the people involved in this event and other researches on Afro-Brazilian music at that time, and, also, the institutions that would may be involved. Other references listed are of works/things/facts/people cited in other parts of the main text, that I believe is also worthy of be accessed here. My intention in publishing my research in full, as well as the dossier related, is to register my process of artistic research and to make clear my motivations and aims in this regard. Important to highlight that some of the documents below cannot be used outside of this work without authorization of the original source/archive. I linked them in the references to be easier to request the rights, if you need.