My latest book, The Trail Behind Me, includes a short memoir titled, "Embracing the Element of Surprise." In it, I give several examples from my youth, growing up in Florida and exploring the wild with my friends, where surprise found us and made our experiences more exciting and memorable.
The element of surprise in music can do the same thing.
When I was going to college in South Florida, eons ago, a band named McKendree Spring gave us a concert one evening. I had no idea what kind of music they played, but it didn't matter. It was the end of a balmy spring day and it felt good just to sit out on the lawn, in front of the stage, and experience something new.
In addition to a number of original songs, McKendree Spring played a cover of "Down by the River" by Neil Young. The first verse was played in much the same style as Neil Young had played it, but when they came to the chorus, they let loose. Fortissimo! Power chords! I was floored. It was totally unexpected. The surprise was exciting. They were loud, and tight, and sounded like The Who had just come on stage for the chorus. Just as exciting was the transition back to the melodic second verse, mezzo-forte.
Since that time, I've come to appreciate a lot of rock music that begins with a soft, melodic intro that changes, with maybe little warning, into something pulsing with volume and energy. (Some classify these songs as power ballads.)
Styx performed several songs like this, including "Lady" (1973), "Suite Madame Blue" (1975), and "Come Sail Away" (1977). Grand Funk did this with a short intro to "Sin's a Good Man's Brother" from the album Closer to Home (1970). And there are many others, including "Glory of the Empire" (2005) by the Norwegian progressive rock band, Circus Maximus. "The Shadow Hunter" (2004) by the Brazilian prog rock band Angra begins with a lively Spanish (Portuguese) guitar and some castanets and up-tempo percussion before (at 0:45) bursting with power chords.
The intros for songs like these are frequently performed on piano or acoustic guitar before electric guitars, bass, and percussion come in with a bang. Certainly, the more you listen to one of these songs, the less the surprise, but even when you expect the shift from "light" to "heavy," it can send a thrill down your spine.