You can take a picture. You can write a song. You can do almost anything well, and it isn't automatically Art.
Different people have their own opinions. To me, something rises to the level of "Art" when two people experience it and take away something unique. That is, their experiences are different.
It's good to talk about your songs. How you were feeling - what led to the song - but don't give too much away. You could write a great song that people love, but too much detail funnels everyones experience in the same direction. You could miss out on interpretations that raise your well crafted song - into Art.
Kids watching Star Trek saw Captain Kirk and Spock as best friends. There were people who saw it much differently. Funny as that sounds; that makes it art. Anything that reaches so deeply into your audience, that different people experience it - unique to their own experience, is truly Art!
I read conflicting explanations about what the movie "Get Out" meant and realized they had created a work of art. To some it was a cool horror movie. To others it was social commentary. But depending on their beliefs, it was saying completely different things! That's Art!
I heard an artist reveal a very specific detail about one of his more popular songs. The audience experienced it in a new way, and that was art too. I saw men wipe away tears just because there was a new context to a story they thought they already knew.
It's another reason to use subtlety and imagery, allegory and all the rest. When many people take away a different meaning to your song, they'll talk about it, argue about it, and remember it.
Keep it up and you'll have a place in their hearts.