I always see this get thrown around when comparing artists or projects. Are we referring to the songs we consider good or bad? Production? Melodies?
higher highs = Xs best is better than Ys best
Lower lows = Xs worst is worse than Ys worst
it’s actually about the frequencies in the song
artist x has frequencies at 24kHz while artist y’s highest frequencies shelf at 22kHz, so artist x has higher highs than artist y