Around about minute 20 he's talking about making the melody less boring, and he says it comes from rhythm, not just pitch. Well, okay, it depends on where you're starting from, but rhythm in a song should build on the lyrics at the best. And then pitch, rhythm and volume work best when they coalesce into a whole supporting the hook/message/content of the song. I've seen that so many times in comments on the user showcase where the music literally rises to the occasion. But also something not on this Berklee lecture is another aspect from the user showcase of where the mix supports the song so that drums and bass and riffs and licks and such all bring the high moments of the songs to the listeners' attention. It's one of the greatest values of the showcase for a lerner like me.