Now "Eclectic" is one word I can't recall meeting in a song; but I've come across it often enough ub wruting or indeed in speech.

"Sibling" is another.

Long words nobody uses are fun - but the ones we use, but don't put in songs are in some ways more interesting. It's not that hard to put one of those overlong words in a song, because they work as a joke. But a short dullish-sounding words don't have that entréé.