I stumbled across the “cup song” by Anna Kendrick (from the movie Pitch Perfect, also performed by her on Letterman and originally learned from a “viral video” which sources to a homemade youtube video by Lulu and the Lampshades).  The trick is singing a short song while tapping out a short percussion sequence using a cup on a table.  For good singers, it sounds pretty good.

The sequence has 11 or 14 elements depending how you count (is “clap twice” one thing or two?).  Either way, it’s pretty short.  It’s also quick to execute. The sequence is repeated a number of times during the song, which is only ~1m long total.

This video, which is a 5m tutorial on how to do the cup-tapping sequence is interesting from a learning and memory perspective.  It is taught by explicit description, then repeated demonstration, in very short chunks 3-4 steps at a time.

http://www.youtube.com/watch?v=qa4BUtsATsg

I think it’s a good example of how we learn sequences, but raises some interesting questions.  Why is it so hard to memorize?  It’s just 14 steps.  Why not use bigger chunks?  Why so much repetition even by the tutor?  Is remembering a timed motor sequence really that hard?  And it’s pretty obvious that verbally memorizing the steps isn’t going to let you perform it fluidly.  Something very important is happening in repeated practice.

Maybe the difficulty of learning a relatively short sequence this way is why it is so surprising that we can see 30-80 item sequence learning in SISL.  If we depend on going through explicit memory to guide performance for initial practice, we’re going to mainly learn pretty short sequences.  The implicit skill learning system isn’t apparently so constrained, though, and pulls structure out of those sequences pretty quickly (~50 reps, regardless of length) if you can get the motor system to go through the steps.