Just like the title says: for any band or solo artist that you know at least a bit, which lyric of theirs best sums up what they’re about? It’s not necessarily the most famous or representative line that we’re looking for, but rather the one that most clearly reflects on the band’s ethos.
So, to start with a really obvious example, the clear choice from the Beatles’ catalogue would be: “All you need is love.”
Your turn. Alternate choices and theories, politely stated, are welcome in all cases.