Progress on the RPM album continues. Five days in, I have seven tracks finished, two more in progress, and I’m hovering around 35 minutes (one of the two minimum requirements of the challenge). And there’s a lot more to come.

The most notable achievement of the day, however, is that I have settled on a final title for the album. I had been tentatively calling it i, owing to the fact that its central conceit is that all sounds on the album are being produced on an iPhone. But I was never totally happy with that title.

Then this morning, it hit me: Pocket Symphonies. The term was coined by Brian Wilson (or, if Wikipedia is to be believed, his publicist Derek Taylor) in 1966, used to describe what might be considered his crowning achievement as a composer and producer: the brilliantly crafted hit single “Good Vibrations”.

It is not my intention in the least to claim that what I’m producing this month is even from the same planet of artistic achievement as the greatest pop single ever recorded. But I think the idea of a “pocket symphony” is intriguing, and while Wilson simply meant that his song packed the compositional structure of a symphony into a 4-minute package, I am taking it in an entirely different direction.

I’ve been asked if I had considered also using my iPad in recording this album. No, is my answer. It’s not that I wouldn’t want to try it; many of the apps I’m using have fuller-featured iPad versions, and there are other great music apps that exist only for the iPad. But the thing that I find most compelling for this project is that every sound on it is coming from a device that I carry around in my pocket.

I suspect that Brian Wilson could not have imagined in 1966 that, in his lifetime, millions of people would be carrying around portable music studios in their pockets, masquerading as phones. And while only a small fraction of us iPhone owners are using them as musical instruments, the potential is there, for everyone. A “pocket symphony” means something in 2012 that was beyond the farthest realm of possibility in the mid-’60s. (Come on, Star Trek had only just premiered a month before “Good Vibrations” was released.)

And so, Pocket Symphonies it is. It’s exciting to watch this nebulous concept begin to take shape as the month wears on.