If you don't have training, melody can be mysterious. Music theory can help, but it's hard to rock out with a tuning fork and a slide rule. Easier to sing into the phone and let Rangula Kala do the math!

Based on the Native Audio example, (C) 2010 The Android Open Source Project, Kiss FFT, (C) 2003-2004 Mark Borgerding, Tentamen Novae Theoriae Mvsicae, (C) 1739 Leonhard Euler, and a few delightful songs from Divya Pillai and Srinivas Sabbella, none of whom should be construed to have endorsed this, or to be in any way liable for it.