The thing is, some records that were highly significant were 78s not albums, e.g. I suspect Machito with Bird and Flip Phillips guesting. Not so much that they could record with such high calibre guests as that the combination of modern jazz's finest with a Latin big band featuring authentic Afro-Cuban rhythms worked so well. I imagine that will have opened a lot of people's eyes and given NY mambo a boost.
Of course. However the specific question is exclusively revolved around LPs. Not 78rpms. I'm sure a solid list could be made during the L.P. era
Those tracks were soon compiled onto album, but maybe by then they had already become significant?
Whether they were or weren't important isn't as significant to the question as it is how significant tgey were from a production perspective. That's the reason the focus is on the LP era. When production value was much higher than the Zeros, 19-teens, '20s, '30s, '40 78 rpm era. Full blown multi-track recording SESSIONS. And not just recordings.
The initial popularity of Celia Cruz with La Sonora Matancera must have been a pivotal moment in Cuban music history - but did a particular album mark her arrival in the public conscious? No idea.
In retrospect, while she had several recordings throughout the 1960s, accompanied by orchestras led by Memo Salamanca, Rene Hernandez, Vicentico Valdes, Tito Puente, and Larry Harlow, in my opinion the LP
"Celia & Johnny" released in 1974, that featured Papo Lucca & Justo Betancourt, in addition to Pacheco and his conjunto, is what fits the bill. In terms of what you described. Marking her arrival, or moreso, marking
a arrival for the 2nd stage of her career. That album had the mega hit
Quimbara and literally reimagined Celia from
La Guarachera de Cuba to
La Reina de la Salsa.
Is CELIA & JOHNNY one of the 10 most important LPs from a production perspective? It certainly is in the running of being so. Just have to look at everything else.