Feel free to review a more natural version below!
If I discounted people with an extreme religious ideology, that see anything related to music as a taboo, I would say that singing has a major significance within my culture, and is omnipresent at every social gathering, whether it is a wedding ceremony or even a simple slumber party involving friends.
Everything you have written seems natural enough, although I have jotted down a few points below that might help you sound more eloquent.
1. The word "subtract" isn't exactly used in the same context as you have, which is why words like "discount", "overlook" or many others are better options.
2. After the word "ideology", "that" is the better option than "who" since you don't know exactly who it is within the section of people with an extreme religious ideology, that opposes music with everything they have. "That" is more general, and hence, more in line with the point you are trying to make.
3. It should be "taboo" instead of "taboos", since the word in question is dependent upon the word "anything" within the sentence, which is singular.
4. "Major significance within my culture" is better than "major significance in my culture", since you know that it is "culture" that you are referring to exactly, as a result of which there is less scope for vagueness, and hence, "is".
5. "Omnipresent" is a natural enough word, which is why I have included the same as an option that you can use, but I would understand if someone made the point that the word in question is used rather infrequently, which is why you are free to use substitutes such as "and occurs at every social gathering", "and happens at every social gathering", "and is indulged in/engaged in at every social gathering", "and materializes at every social gathering" or perhaps an easy substitute such as "and is done at every social gathering".
6. "Party involving friends" is more natural than "party between friends".