Sunday 24 June 2012

Cross - Connecting

Hi all. Once again my friend CKM has come up with some thoughtful responses to a piano lesson with me. In the lessons we are gradually getting to work on techniques and dynamics/articulations in bebop heads, a great resource for building jazz language skills. These particular thoughts to my mind, essentially deal with the 'Macro and Micro' dynamics and articulation choices in piano jazz. There truly is no 'one' way to play lines and figures (unless agreed upon in an ensemble situation). So I humbly submit the following thoughts from one who brings many insightful thoughts and perspectives. What else would you expect from a math/computer/engineer/genius-nice person ? !! (I'm "C". in this monologue).

Cross-connecting (by CKM).


Cross-connecting.

I liked that lesson today.   We just went over most the of the songs, working on dynamics and articulation and swing and all that stuff.   I'm kind of feeling for the first time that I'm generalizing correctly about all kinds of things in that domain.  The expression markings I'd written in on several of the songs were good for the most part.   Some of those were based on listening to how C played them on the recording last week, but some of them were just that I thought it sounded right a certain way because it instantiated a certain pattern that I recognized from another song.

It's a neural net training problem really.  When you design software neural nets to solve a problem (neural nets simulate the brain directly in a simple sense, in terms of the neuron connections and strengthening connections that are used and building associations) you have to train the net on the problem domain.  A typical application of a neural net might be facial recognition, and you would train the software by showing it a number of pictures of the subject it was being taught to recognize.   It's a little tricky, because it's important to get the size of the training set right.  If you show too few pictures of the subject, the net won't have enough information to generalize, and won't recognize other similar pictures.  But, perhaps surprisingly, if you show too many pictures of the subject, the net will become "over-trained" and will think it has a perfect and complete understanding of the subject, and nothing can be added to it, so it won't recognize new pictures of the subject very well either, because they are different from the pictures it knows about.   Its understanding is over-specific and normal variation messes it up.

Anyway, I think broadly speaking I've been suffering from too few items in the training set, largely because of not having spent decades listening to this music, and although I have worked on lots of songs, because I've worked on them sequentially, there has been limited carry-over of pattern recognition from one song to the next.  Each one has been a whole new adventure.  Which has been fun, but it's certainly being useful in a different way to have the patterns from a dozen songs all in my mind at once, because there are cross-connections every which way, and it makes it easy to see them.

Sometimes, in another sense, I get too many items in the training set, like when I want C to specify every microscopic dynamic in a line, but it just doesn't matter all that much.  There are situations where there is some essential characteristic that needs to be kept, but the tiny details can be done many different ways, but I don't distinguish those two categories.   From a neural net perspective, it's desirable for the net to identify the essential characteristic, and be flexible about the rest of it, but is overtraining when the net perceives the non-essential characteristics as part of the essential identity.  But how to tell the difference?  That's the tricky training set size and content thing, and even with software, de facto it gets worked out on a trial and error basis until you come up with the right approach for the problem domain.

I wasn't thinking about any of this, this morning though.  I was thinking lift & drop, putting weight into keys, using the weight of my arm to roll into notes and phrases, and keeping relaxed, and trying to always make phrases be going somewhere dynamically, never just sitting there, and just trying to be totally focused on whatever we were working on.   That kind kind of focus just makes me so happy, both at the time, and thinking about it later.

Austinato: We had a further dialogue to kind of tie things together—Thank you dear reader:

  1. austinatoJune 21, 2012 11:54 PM
    Uh huh !!

    I love this... It would benefit others to hear about this... because in my limited scope here, what your saying here is correct. It's akin to balance when playing: don't try too hard and conversely don't try to little. Balance of the musical forces. It would be hard to phrase the exact same way every time but if you are in the groove and in the moment, one can balance the dynamics as you proceed. It's processual !!






    1. CKM: This: "It would be hard to phrase the exact same way every time but if you are in the groove and in the moment, one can balance the dynamics as you proceed."

      It has to end up like that.
    2. austinatoJune 22, 2012 10:03 AM
      I think it becomes what is called by many: intuitive.
    3. austinatoJune 22, 2012 4:49 PM
      This is a key:" Its understanding is over-specific and normal variation messes it up".

      Heavy duty is this: There are situations where there is some essential characteristic that needs to be kept, but the tiny details can be done many different ways,

      and this: it's desirable for the net to identify the essential characteristic, and be flexible about the rest of it, but is overtraining when the net perceives the non-essential characteristics as part of the essential identity....Oh Yeah !!

  2. austinatoJune 22, 2012 5:05 PM
    That's not to say that the plethora of detail infinitudes, should be ignored. They 'play' a big part in the shape and vitality of a line
    .

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