Its very specific, it's the title of a video and I don't know if somehow the joke is that it's clearly grammatically incorrect, if it's a saying or something but it just sounds wrong and i'm going crazy. Is it grammatically correct? I don't know how else to look it up since i don't want to replace anything in it in case its just a joke or something.
It's obviously grammatically incorrect.
Is it a joke? Perhaps. I looked at the video and the creator seems perfectly literate and a native English speaker. When he uses this phrase and other bad English in his slide presentation it is quite jarring and a contrast from everything else he is saying.
I did wonder if it was meant to be reminiscent of the deliberately bad grammar of 'lolspeak' memes popularised in the 2000s on 4Chan, such as "I Can Has Cheezburger?", but that is particularly dated now and I see that this is a brand new video.
I think it is more likely to be an 'in-joke', meaning a joke aimed at a very specific audience that will get it because the creator knows what they already know. Perhaps if you are familiar with his other content, you may recognise it as a running theme, or a callback to something previously said.
Update A helpful comment has connected it to this meme. I agree this is almost certainly the reference.
Yes, it's grammatically incorrect.
The correct phrasing would be, "Is the song 'Piano Man' gay?"
"Does" as an interrogative verb indicates some action. It is always accompanied by another verb to indicate what action. Like, "Does George drive a bus?" "Does the building have large windows?" Etc.
If you are asking about an attribute of something, an adjective that might describe it, you use "is". "Is George tall?" "Is the building gray?" Etc.
As @astralbee says, there might be some kind of joke here. Personally I don't see anything about the song "Piano Man" that makes me think of homosexuality. Maybe I'm missing something. Possibly the speaker means the old definition of "gay", "happy and carefree". If so the answer is still no, as the song is rather melancholy.
It’s not only grammatically incorrect, but it uses the word “gay“ as a pejorative meaning “bad“ in the general sense, which is not really done anymore. Unless the song “The Piano Man“ is about the love affair between two men, for example - in that case the song refers to a gay relationship but whether the song is itself gay is another question to be determined… can a song be gay? It can in the old fashioned sense of ‘cheery’.