I just discovered JET Powered Apps’s Rhythm Calculator app, a gem of an app I guarantee will live on my phone for quite some time, and I suspect that’ll be true for you other iOS device-carrying folks as well.

Rhythm Calculator is exactly what the name suggests: an interface that allows you to enter rhythms of most any type, in the familiar iOS calculator-like presentation. Once entered, hit the “=” sign, and the app will play the rhythm for you.

The app supports various time signatures, ties, note and rest values up to 1/128, any tuplet grouping and dotted rhythms.

A quick hold on the Tuplet button allows you to select your tuplet type, a quick hold on the dot allows you to select single, double or triple dots for your note values while a short hold on the “=” button brings up the spring-board for help, time signature selection and selection your beats per minute.

The ways in which I could find uses for this app are almost endless. Primarily, I imagine coming across a tricky rhythm in a song and being able to later shed that rhythm to really internalize it, just by entering it exactly as written into Rhythm Calculator.

This could also be handy when transcribing. If you’re not sure how to notate a passage, you can experiment within the app to find the correct rhythmic notation before committing it to paper.

At $1.99, most serious students and practitioners of music would be remiss if they didn’t check this app out. It’s very clean, very simple to use, and very accurate. It allows you to get right to the heart of what you’re there to do with no fuss and no muss.

Rhythm Calculator is available from the App Store and is compatible with iPhone 3GS, iPhone 4, iPhone 4S, iPod touch (3rd generation), iPod touch (4th generation) and iPad. The app requires iOS 5.1 or later.

Rhythm Calculator Overview: