The keyword phrase "patriots day zac brown band song" functions grammatically as a noun phrase. The core part of speech that serves as the main point of the phrase is a noun.
In this construction, the word "song" is the head noun, the central element being identified. The preceding proper nouns, "Patriots Day" and "Zac Brown Band," act as adjectival modifiers, also known as noun adjuncts. They work together to specify and describe the head noun, answering the question "Which song?". "Patriots Day" likely refers to the song's title or theme, while "Zac Brown Band" identifies the artist. The entire collection of words operates as a single unit to name a specific, unique entity.
For the article, this determination is crucial because it establishes the keyword as a specific thing. The phrase should be treated as a singular concepta particular musical work. This allows the keyword to be used as a subject, object, or complement in a sentence, correctly positioning the song itself as the primary topic of the article.