How to Learn a Song by Ear with Stems: Isolate, Slow Down, Loop
Learning a song by ear is the skill that separates players who need a tab for everything from players who can pick up a part at rehearsal. It is also the skill most people give up on, because a full mix hides the part you are after behind five others. Stems take that excuse away. This is the method, instrument by instrument, with the tools that make it work.
Why the mix is the problem
A bass line under a distorted guitar, a piano voicing inside a wall of synths, the second vocal in a chorus: the notes are there, but your ear cannot pull them out of the mix, so you guess, and guesses turn into wrong notes you then have to unlearn. Every trick musicians used for this, from EQ-ing the treble off to slowing a tape down an octave, was an attempt to hear one part on its own. A stem player does exactly that, cleanly: split the song into vocals, drums, bass, guitar, piano and the rest, and solo the one you need.
The method
Four moves, in this order. Skipping the order is how people end up learning a part wrong.
- Solo the stem. Hear only the part you are learning, at full speed, once or twice through. You are not playing yet; you are finding where the part lives in the song and what it does in each section.
- Slow the passage down. Drop to 60 or 70 percent with the pitch untouched. At half speed a fast run becomes single notes you can name. Because the key does not move, what you hear at 60 percent is what you will play at 100.
- Loop the bar you cannot get. Two bars, not the whole verse. Play it round until your fingers find it, then widen the loop to four bars, then the section.
- Put the band back. Unmute everything, take your own instrument out, and play the part against the rest. This is the step that turns a memorised shape into a part you can hold in time with other people.
Bass
The bass is the part most often learned wrong, because in a mix you hear its rhythm and guess its notes. Solo the bass stem and the actual notes appear: the passing tones, the slide into the chorus, the octave jump you never noticed. Check the root of each bar first, then fill in what happens between the roots. Slowing down helps with the fast fills; for the rest, full speed with the bass alone is usually enough.
Then flip it: mute the bass and play it yourself against drums, guitar and vocals. If you lock with the kick drum, you have it.
Guitar
Rhythm parts hide voicings. Solo the guitar stem and listen for how many strings are actually ringing and where the chord sits on the neck; a G that sounds like a G in the mix is often a partial shape up the neck once you hear it alone. For a lead line, slow the phrase to 60 percent and loop it two bars at a time. Bends and slides survive time-stretching well; fast picking blurs a little below 50 percent, so do not go lower than you need.
One caveat: when a song has two guitars, separation puts both on the same stem. Pan and tone still tell them apart, and slowing down makes the two lines easier to follow separately.
Keys and piano
Piano voicings are the hardest thing to hear in a full mix and the easiest with a stem. Solo the piano stem, slow it down, and take the left hand and right hand separately: loop a bar, find the bass note, then find the top note of the chord, then what is in between. Organ and synth pads land on the "other" stem, which is less clean, but soloing it still tells you the chord movement.
Drums
Drummers learn songs by ear all the time; the problem is the fills and the ghost notes that the guitars cover. Solo the drum stem, slow the fill to 70 percent, and count it. Then mute the drums entirely and play the song with the rest of the band: that is the closest thing to the gig you can get in a bedroom, and it shows immediately whether your tempo holds where the drummer's did.
Vocals and harmonies
The lead is usually easy to hear. The harmonies are not, and they sit on the same stem as the lead. Solo the vocal stem, and the harmony is at least no longer buried under the band; slow the chorus down and the interval becomes clear. To practise your own harmony, keep the vocal stem in but low, so the lead guides you without drowning you out.
Common traps
- Learning at half speed and never coming back up. Raise the tempo in steps: 60, 75, 90, 100. A part you can only play slowly is not learned yet.
- Looping too much at once. The loop should be the bar you get wrong, not the section that contains it.
- Trusting the stem over your ear. Separation is not perfect. A note that sounds odd in the solo stem may be bleed from another instrument; check it against the full mix before you learn it.
- Skipping step four. Playing along with the whole band, your part muted, is the only test that counts. Do it before you call a song done.
From practice to the stage
Once the part is yours, the same mix becomes a backing track: mute what your band plays live, keep what you cannot cover, export the WAV. Give it a count-in that lands on beat one and put it in your singer's key with CountIn, the sibling tool built for that last step.
Frequently asked questions
Does slowing a song down change the pitch?
Not in a tool built for practice. Time-stretching changes the speed and leaves the key where it is, so a part learned at 60 percent is the same notes at full speed. If a tool drops the pitch as it slows, it is playing the audio slower, not stretching it, and it will teach you the wrong key.
How slow should I go?
As slow as you need to name the notes, and no slower. For most parts 70 percent is enough; fast runs and fills may need 50. Below that, fast passages start to blur, and you also lose the feel of the groove.
Can I isolate one guitar when a song has two?
Not as separate stems: separation puts all the guitars on one channel. What you can do is solo the guitar stem, slow it down, and follow each line by its tone and position in the stereo picture. It is still far easier than hearing them inside the full mix.
Is it cheating to learn from stems instead of the full song?
No more than a slowed-down record was for the generation before. The ear training happens when you name the notes and play them back; the stem just removes the guessing about what you are hearing. Step four, playing against the band with your part muted, is where the real listening returns.
Is StemPlayer free for this?
Yes, while in beta: two songs a day, six stems each, no account, in the browser.