If you can hum a riff, it’s often easier to figure out how far apart each note is on the fretboard. It goes both ways: singing a riff can help you to transfer it to guitar, while learning a riff on guitar and then transferring it to vocals can teach your subconscious self all sorts of helpful things about melody and rhythm that might not be apparent from looking at the fretboard. This is stuff that can help you whether you’re learning by ear and experimentation, or if you’re taking a more guided, theoretical approach to guitar. When you come down to it, every note we hear in western music is one of the twelve notes of the chromatic scale, so once your ear gets used to distinguishing the differences in distance between each note, the whole fretboard - nay, the whole nature of music itself - opens right up. It gets much easier to figure out songs when you can hear any two notes and just know how many frets lie between them. But this can be a tricky skill to develop without some kind of guide posts, so it can be very helpful to train your ears to recognize specific intervals. Here are some of the key ones and how you can recognize them.
Half Step (1 fret)
There’s a particularly iconic piece of music that really personifies the menace, mournfulness and might of the half-step interval: the ‘uh-oh, the shark is coming’ music from Jaws. Pick a fret - any fret - play that note, then play the next highest note. Sounds spooky, right? Once you’ve got that under your fingers, try playing it in reverse, going from one fret to the next lowest fret. This is the interval you’ll hear in the main riff of Ministry’s “New World Order.” And it’s the basis of more metal riffs than we could ever count. Megadeth’s “Symphony Of Destruction” is a particularly brutal example.
Whole Step (2 frets)
The whole-step interval (two frets) seems to be more of a ‘transitional’ one: many players tend to use it on their way through to another interval that more clearly defines the harmonic movement of a riff. But one of the most dramatic uses of this interval is the opening rhythm punch of Metallica’s “For Whom The Bell Tolls.” Kicking off with two sets of doubled-up F#5 power chords at the second fret of the low E string before dropping down to an open position E5 chord, this riff is packed with energy. This is also the interval of the first two chords of Cream’s “Sunshine Of Your Love.” Spin it around the other way from lower note to higher one and you’ve got the interval from the verse of Van Halen’s “Everybody Wants Some!” or the beginning of Sabbath’s “Sabbath Bloody Sabbath.”
1 1/2 Steps (3 frets)
This is where things really get interesting: the sheer number of rock, metal and blues songs that hinge on this interval is utterly overwhelming. This gap of three frets is what you’ll hear in the first two chords of Black Sabbath’s “Iron Man,” Deep Purple’s “Smoke On The Water,” Everclear’s “Santa Monica,” Metallica’s “Fuel,” Joe Satriani’s “The Extremist,” Led Zeppelin’s “Whole Lotta Love” and many, many more.
2 1/2 Steps (5 frets)
This one is easily recognizable as the sound of two adjacent strings (ignoring, for a moment, the little tuning mismatch between the G and B strings on a standard guitar). Play an open A string, then play an open D string: that’s this interval (also known as a major fourth). This is the one that you’ll hear in the first two notes or chords of things like “Wild Thing,” Green Day’s “When I Come Around,” Nirvana’s “Smells Like Teen Spirit” and heaps more.
3 1/2 Steps (7 frets)
This is the same distance between the two notes of a typical Power Chord. It’s also the first two notes of the main melodies of the Flintstones theme, the first interval of “Twinkle Twinkle Little Star,” the first two notes of Chris DeGarmo’s delay-drenched lead melody in Queensryche’s “Jet City Woman,” the fast back-and-forth riff of The Easybeats’ “Friday On My Mind” and jillions more.
Bonus Interval: 3 Steps (6 Frets)
Aah, we’ve talked about this one before: Diabolos In Musica, the Evil Interval, the spookiest-sounding interval ever. Black Sabbath’s “Black Sabbath” and “Symptom Of The Universe” are great examples of this one.