There are drum machines, there are beatboxes, and then there’s Impaktor, an entirely original iOS drum synthesizer that uses your fingers and a tabletop to make the rhythm happen. It’s an odd approach, but one that really works for quickly making some nice beats, so long as you have headphones as well. It’s totally fun, but there’s also some real audio-sculpting depth under the hood.

Impaktor marries a drum-oriented synthesizer with your iOS device’s ability to use its microphone as an audio trigger; essentially, you lay your iPhone, iPod touch, or iPad down on a flat surface and use your fingers tapping on the surface to trigger the drum synth. As expected, there are controls for adjusting the sensitivity of the microphone, which is crucial in dealing with using the app in a relatively loud environment. As it is, you’ll most likely want to avoid whipping this out at your local coffee shop or a rowdy party, since the ambient noise will likely interfere with your attempts at tabletop drumming.

The app includes six presets, which are configurations of the four primary synthesized tones (Membrane, Resonator, Noise and Frequency Modulation), delivering some really interesting harmonic offerings such as “Rost Pock” and “Noise Bag." Each basic tone offers some deep tonal controls and options, and there’s plenty of sonic flexibility here for the adventurous.

You can record up to six tracks of overdubbed drum beats, each with a different sound, if you like; plus there’s a quantization option, which forces your drum hits into a specific tempo synchronization, making your recorded playing sound like it’s right on the beat. Recorded sessions can be exported as WAV files or moved to other apps via Audio Copy, as well as emailed, but there’s no support for Dropbox or other cloud storage, sadly.

The bottom line. The sheer amount of sonic power and flexibility will bring a smile to any musician's face, and the instant gratification factor of Impaktor makes it a classic iOS music app.