Wednesday, April 27, 2022

Distinguishing between very similar musical lines during practice sessions

I’ve been practicing (the melody of) a 12-bar blues that I’ve created, “Skippy’s Blues.” Bars 3, 7, and 11 are identical. Bars 4, 8, and 12 are each almost like the preceding bar, but they differ in the final 3 notes, which are an eight-note triplet leading in to the next measure. So, I’ve got three 2-bar phrases – 3 & 4, 7 & 8, and 11 & 12 – which are identical except on the final beat. Let me recast that: I’ve got 3 8-beat phrases that are identical except for the 8th beat.

Why am I expending so much energy describing this? Because I keep confusing those phrases in the last beat. I note that I’ve not written the melody down, so I’m practicing it “by ear,” as the saying goes. I must have played it 20, 30, 40, who knows how many times over the last three days or so. I’m getting better, but keeping those phrases distinguished from one another and executing the right phrase for the context, that’s very tricky. What makes it tricky is that the phrases are identical for 7/8ths of their span.

Every once in awhile I get it right. But on those occasions I’m still thinking ahead, and there may be a bit of hesitation on that last beat of the phrase. How many times will I have to repeat the whole melody until I get those phrases right? The idea is to play it through without thinking about.

I assume that the problem is in the motor system. I haven’t been keeping track, so I don’t know whether or not it’s trying to play the previous version. That is, in bar 8 it wants to play what it had done in bar 4, in bar 12 it wants to play what it had done in bar 8, and then in bar 8 it wants to play what it had done in bar 12. It would be interesting to keep track, but also tedious beyond belief, so I won’t do it.

What’s going on? Is the motor system trying to ‘compile’ one phrase with a variable last beat, depending on context? Or is it trying to learn three different phrases, which happen to be almost identical? I don’t know. Which would be the best way to do? Do I have any conscious choice in the matter?

Yes, this is ultimately about the motor system, but also about the relationship between the motor system and auditory perception and attention. It seems to me that, since I don’t have it down at the moment, the attention system is trying to interrupt the motor system near the end of the phrase so as to stear it to the proper ending. That doesn’t seem to working. Maybe the idea is to play it slowly enough so that I can get it smooth without interruption. Once I’ve got that down, then I can start gradually speeding up.

This is the kind of thing that forces musicians to practice hours and hours and hours. Athletes, too.

Coda: And, you know, I suspect that getting really good at arithmatic calculation poses similar problems. It’s not so much about moving the pencil around – but remember all that time you spent practing letter forms and word forms in learning to write? – but keeping track of where you are. The brain, after all, is a physical mechanism. Keeping track is thus a physical process. See my earlier post, Why is simple arithmetic difficult for deep learning systems?

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