As musicians, our lives are built around the tonic chord (I) of a song. It’s like our home … which is a pleasant place to spend much of our time. But to keep things interesting, we also have to venture out every once in a while. Otherwise, life might start to get a little boring. So we need to put on our walking shoes and go for a stroll through the neighborhood.

Just like a bunch of friends and neighbors, the other chords are waiting for us to visit. We could drop in and say “hello” to any of them. But our closest friends are the subdominant chord (IV) and the dominant chord (V). That’s because, back in the day, they used to live right next to the tonic (I) in the circle of fifths. In fact, chords IV and V get along so well with the tonic chord (I), that they’re almost like family.

In every key, the tonic chord (I) and the dominant chord (V) are especially good friends. And so you’ll often see progressions that move back and forth between just these two chords. The motion between them is so smooth and natural that it feels like we’re floating along a nicely paved path.

To get a feel for this simple “I–V–I” progression, try moving back and forth between these two chords. Almost immediately, we can create a very smooth forward motion that sounds hypnotic. Like a pair of magnets, the dominant (V) naturally pulls away from, and easily leads back to, the tonic (I).

Starting at the tonic (I), it’s easy to move toward the dominant (V). But of course, we don’t want to wear out our welcome, so we stay only for a short time. Soon enough, we turn back and walk home to the tonic (I). The gradual flow between these chords sound great. And it keeps things fresh and interesting.

The effect is so pleasing that some songs use only these two chords. For example, check out the song “Mary Had a Little Lamb” in the key of C. Using only the C major chord (I) and the G major chord (V), we can form a complete progression. Like a Sunday stroll to our friend’s house, we start out at home and eventually return after a couple of short visits.

To help us keep track of which chords to play, chord symbols are also included above the staff lines. You might think of these labels as a kind of musical shorthand for each chord. Sometimes, musicians just follow these symbols as they play through a song. But honestly, you can do what you want. So if you prefer, you can simply keep an eye on the notes that are written on the grand staff. And remember it’s okay glance down at the keyboard every once in a while … just to make sure your hands are moving to the correct position. Like always, the more we practice, the better we’ll get.