The other evening, I was teaching a young lad called Lenny how to play Black Dog by Led Zeppelin. We were working on the fiddly bit that comes in two bars into the chorus.
I showed him how to play it, and he played it straight back to me, quite wrong, then looked up at me as if to say, “yep, got it.”
So I told him it wasn’t quite right and showed him again. He played it back. Same mistakes, exactly. This time I pointed out what he was doing wrong and what to do instead. He played it back. Still wrong. And still that same look, certain he’d nailed it.
In the end, I took out my phone and filmed him playing. I wanted Lenny to see himself making the mistake. He played it wrong, of course, but the moment he watched it back on the screen, he spotted the error instantly and put it right.
So what was going on?
Two types of feedback
Immediate feedback is feedback you get as you’re doing something, or the second you’ve finished. Watching yourself practise in a mirror is a good example — you’re getting feedback in real time. So is a teacher telling you you’ve got it right or wrong the moment you’ve played it, which is what I was doing with Lenny.
Delayed feedback is feedback you get after you’ve practised. Think of someone learning golf: the coach films the student’s swing, then plays it back afterwards to show them what’s working and what isn’t. The feedback comes later, once the swing is done.
So which one works better?
Here’s the interesting part. The science seems to suggest that feedback we get while we’re learning can actually get in the way. The problem is that we end up trying to do two things at once — practising the skill and watching ourselves do it — and our attention gets split between the two.
Delayed feedback dodges this. Because it comes afterwards, we can give our full attention to the practice first, and then our full attention to the feedback. Nothing’s competing.
I think there’s something else going on too. When the feedback is delayed, we take our mistakes in properly — we’re fully focussed on them, with nothing else to think about. When we’re getting feedback mid-practice, we don’t absorb it as well, because part of our brain is still busy playing.
And then there’s the simple fact that video lets you see things you’d otherwise miss. This is the bit I find most useful. A skill often feels right while you’re doing it, even when what’s actually happening is quite different — and you’ve no way of knowing until you watch it back. I recently caught a strange little habit in my right-hand fingerpicking that I’d never once noticed in years of playing, just from watching a video of myself.
That, I think, was really Lenny’s problem. While he was playing, he couldn’t feel the mistake — so no amount of me telling him made it real. But the second he could see it on screen, there was nothing to argue with. He fixed it himself.
What this means for your practice
If you’re stuck on something and can’t work out why, try filming yourself and watching it back. Play first, review after — don’t try to do both at once. You’ll usually focus better, and you’ll often catch the thing you couldn’t feel in the moment.