Brilliant, because it looks like you will become a great novelist some day, and stupid, because you using crypto seed phrase, how is that a song anyway? This days that are so desperate with everything they do, I have seen people guessing seed phrases and putting them together hoping they get into someone's crypto wallet. Thanks for giving them this clue, now they can go buy novel books and start inserting words themselves.
I do not think it is stupid to put seeds in a song but teaching the kids of that song is. Using seeds phrase in a song is brilliant making it not obvious to be a seed phrase unless @OP declare that it contains his seed phrases. He can always take care of the piece that contains the seed phrase just like the seed phrase itself. Creating a copy, laminating or printing it then store it where the element of nature can't destroy it. This way when someone got the copy of that song have no idea that seed phrase are integrated to it.
I have in no way stored my recovery seed online, thinking it's safe, it's a bad practice, I would rather find a book and write down my recovery phrases and keep the book safe, if you don't have money for a hardware wallet it's better to get a book and write down your seed phrase.
Important information such as seed phrase and private keys should be stored out of the internet. The reason behind is that, there is no safe place in the internet especially the known storage sites since hackers will always try to hack it.