How to recreate the synth lead inTake On Me by a-ha

The original riff was played on a Roland Juno-60, doubled with a second synth (accounts differ — a DX7, a PPG Wave, or simply a second Juno). You can get very close with one synth.

The things that actually matter:

1. It's very plucky. The amp envelope is the whole trick: zero attack, a medium decay, and sustain all the way down. Each note blooms and immediately falls away. If you hold a note and it just sits there, your sustain is too high.
2. Square wave on top, saw wave an octave below. The square gives it that hollow, reedy character, the saw underneath adds weight so the riff doesn't sound thin.
3. Filter envelope does the heavy lifting. Set the cutoff quite low then push the envelope amount near maximum. You want to hear the filter snap open on every note. That percussive bite is what makes the riff cut through.
4. Chorus is a must. The Juno's onboard chorus is a huge part of this sound. Roughly half-wet, on the faster side.
5. A touch of resonance sharpens the filter snap.

If your synth has a unison or voice-stacking mode, two lightly detuned voices thicken it up nicely and help fake that "doubled by a second keyboard" quality.