If the Pulsate iOS app looks familiar, perhaps you've encountered one of its predecessors, ToneMatrix, which attracted lots of attention by pairing a simple musical idea with a minimal, elegant interface.
Pulsate ($1), from Audiotool, is similar to ToneMatrix in that it requires no previous musical knowledge in order to use it (you can also try it in Flash on Michelle's site). With an interface consisting of unadorned orange circles set against a flat black background, Pulsate has every bit of the utilitarian good looks of ToneMatrix, albeit with more involved functionality.
(Check out more ways to make music without really trying.)
Tap the screen to create a circle, which starts to grow. Tap again to create a second. When these two circles collide with each other, each produces a tone corresponding to its size; the bigger the circle is, the lower the tone. There appears to be no limit to the number of circles you can create, and each adds sonic complexity, although from a user perspective, all you have to do is keep tapping.
Controllable parameters include tempo, waveform, attack, and decay, much like with NodeBeat. These nice controls will appeal to the geekier set (present company included), but we suspect most users will find them to be unnecessary. There's a simple appeal to tapping spots and seeing what happens that isn't really enhanced by that kind of knob-twiddling precision.
The app includes a disclaimer: "Designed for headphones." We couldn't agree more (especially because AirPlay doesn't work with interactive apps like this). Without headphones, the app seemed somewhat impressive, but it was far from revelatory.
Putting on a good pair, though, changed everything. The use of stereo -- with sounds panned left and right according to the circles' on-screen location, offers a far more immersive experience.
It remains to be seen whether Pulsate will generate the same kind of enthusiasm that ToneMatrix and Audiotool have. However, it does mean that when it comes to matching inspiring visuals with equally wowing sound, Michelle and Co. are emerging as a force to be reckoned with.
Pulsate is a simple app which allows you to create musical patterns from randomly colliding circles. Sit back, watch the circles collide and listen to the evolving melodies.
Note: Pulsate makes use of cutting-edge browser technology and requires a fast computer to run smoothly.