If you're not following any existing form, it becomes encumbant on you to construct the form anew. Without form, you'll have real difficulty making the song listenable beyond a certain length. It's the same with programming. Beyond a few thousand lines, the lack of structure makes the entire enterprise unweildy.

So it is very useful to learn how to follow this or that form, so you can steal little bits of structure.

Eg. I had a little guitar riff that was very catchy. You could speed it up, slow it down, add drones, lead lines. But I could not, for the life of me, make it go anywhere. When I finally began to wonder why, theory showed the way. The riff was essentially a 2-measure chord progression: I / / / | V / / /. I couldn't start a new phrase (bridge/chorus/anything "different but the same") on V because I was already there. So I had to steal pieces from other forms: deceptive cadence or "sitting" on I the last time round (of some binary repetitions) [this one actually makes the "new phrase on V" possible]. 

On the otherhand, it can be very interesting to start out following a form, and then radically depart from it. So you will find it useful to be aware of forms, so you can make conscious choices about when to follow, when to lead.

In other words, Knowledge of Forms is the glue you put under your shoes in order to stand on the Shoulders of Giants.

Does following "musical forms" suppress "creativity"?
I have an old cheap keyboard which spans 5 octaves plus one extra C, so it goes from C2-C7 (I think).

Does that make this a 41 (5 x 8 +1) key or a 61 (5 x 12 + 1) keyboard?

When we talk about a standard 88-key piano is that the total number of white and black notes, meaning it covers just over 7 octaves?

While I'm here, what are the standard keyboard configurations if any other than a traditional piano can be said to be standard?
