Okay my attempt was;

Знаешь ли эту песню перед этим было знаменитым?

My chain of thought;

[Знаешь ли] Presently tense, 2nd person, do you know?

[эту песно] using declined этот as I am talking about a specific thing. Feminine accusative

[перед] Prepositional which modifies the following word to instrumental...

[этим] Unchanging это in instrumental form as "IT" rather than "THIS" feels more natural in English.

[было] to mean was, and as we are now using IT i thought I would decline to neutral.

[знаменитым] and finally famous in the instrumental case as I was told that past/future (predicates) i think they are called, are in the instrumental case, again neutral due to этим being used.

Now, slaughter me for bad grammar and tell me where my logic is wrong.