It's the HOOK. Ya gots to have da HOOK.......and that is the hardest thing to come by. Very good meter helps immensely as well. Lyrics-what a joke! Most pop music is filled with the most irrelevant, vapid, worthless, lyrics. The product of a plastic society I guess. So my conclusion: hook and meter and maybe not too much of a gratuitous display of superior musicianship. Solos are there for the song not the other way around.