May 25, 2012 in News
I wanted to give a quick look at the (currently very minimal/ugly) iPad interface I’m working on.
So here’s what you are looking at:
There are 7 pitch rows in this image (divided by the horizontal white lines). Each pitch row is basically like a string: a continuous range of pitches going from low on the left to high on the right. The main difference from a physical string is that here pitch is mapped linearly rather than logarithmically. In other words: notes are equally spaced. Here the pitch rows are tuned a just perfect forth (4:3) from bottom to top, similar to a bass. Equal tempered half steps are denoted by the light and dark cyan vertical lines (“black keys” being the darker lines), with C always being the magenta looking one (to tell where you are). The circles are showing where my fingers are in this instance and the radius is how much finger is down (psudo-pressure sensing!).
The interesting part are all the diagonal lines. These are basically guides to help you visually tune intervals in just intonation. If you look at the cyan circle you’ll see a blue vertical line passing through the center. This shows where a just perfect forth (4:3) is. The blue diagonal going from bottom left to top right shows where a just fifth (3:2) is, which is where my second finger (the white circle) is. As these lines are transparant, when you line them up they get a little brighter, thus helping to show when you are in tune. The green lines are major (5:4) and minor (6:5) thirds and the yellow are 7:6 and 8:7 (just minor 7th). The short white vertical lines show where octaves of pitches you are touching are and also display the colored diagonal lines (which I’m calling ratio guides). And as a quick aside, see the equal tempered pitch indicators are slightly offset from row to row? This is because they are not in tune with their just counterparts. Here you can see exactly how much they differ.
“So what exactly does this do?” you might be asking? Well, lots and lots more soon!
First off I’d like to say that I can’t take credit for the pitch row and ratio guide concept. Those are ideas I got from Rob Fielding (a very innovative iOS instrument developer), specifically from his app Geo Synthesizer, which I absolutely love. Rob, like myself, is extremely interested in creating interfaces designed with microtonality in mind. His first app, Mugician, was one of the first things I tried when I got an iPad (and I must once again say thank you to my ex-wife and her family for that) and it blew me away. Geo was Mugician on steroids: introducing the ratio guides, the ability to scale the view for greater pitch control, and polyphonic microtonal MIDI output. I’ve performed with it a number of times and highly recommend it.
It does however possess a few limitations when it comes to my needs. Specifically:
- I much prefer OSC to MIDI as I use SuperCollider as my primary audio engine, and that also doesn’t limit me to a resolution of 0-127
- the official release does not have finger area sensitivity
- I can see situations where I would want to alter the tuning between rows or add/remove ratio guides
These needs led me to develop Un:Limit. The name is a play on just intonation terms. Ratios are typically written as #:#, “limit” refers to the highest prime number involved in the ratio, and I’m making this as versatile as possible. Not only does this send data as OSC (currently frequency, vertical position within the pitch row, and finger area) but it also allows you to:
- tell it how many pitch rows you want
- say how wide each row is in fractional MIDI pitches
- tell it what the bottom left corner’s pitch is
- specify what the ratio between each row is
- add/remove ratio lines as needed
- specify what IP and port to send it’s messages to
all via OSC! This will allow the basic interface to be fine tuned to specific situations as needed. Currently the app does not have any on-board audio capabilities but that may be added later if I feel the need to do so.
This is a project that I have been working on for about 9 months off and on (mostly off) at this point. I hope to also add some other GUI elements (sliders, etc.) soon for extra control directly from the iPad. Ultimately, Un:Limit will be one (rather small) part of my doctoral dissertation for my upcoming show. More on this (and the show in general) soon!