Using Indefinite Articles (A/An) Before Uncountable Nouns

We have all studied that we can't use indefinite articles (A or An) before uncountable nouns. As a matter of fact, we can use indefinite articles before uncountable nouns if we refer to specific ones.

Uncountable Nouns means nouns that we can't count. For the same reason counting them with an indefinite article is not reasonable. However, it is the teaching for beginners. When you reach an advanced level, you can find plenty of instances of indefinite pronouns coming before uncountable nouns. In these instances, we are not actually counting them; instead, we are meaning "certain kind of a." 

The land was invaded by deadly pollution. (it is a general idea; there is no article).

The land was invaded by a deadly pollution. (we are trying to specify the pollution by alluding to its intensity, nature, or cause; it tends to mean some kind of a)

The usage of indefinite pronouns before uncountable nouns is plenty to see at places where such uncountable nouns are followed by a relative clause whose function is just to specify it. For example, love is an uncountable noun.

However, we put an indefinite article before it when we specify it as "some kind of a".

I have a love for her that no time could ever take away from me.

However, still there are a lot of uncountable nouns that still do not approve of indefinite articles; for example, music. We can never say "a music" even if we specify it because it is always a blanket term with broader conveyance of meaning.