Hi,

This is probably a very simple issue to resolve, but I’d be grateful if someone were willing to point out where I’m going wrong.

I’m still basically a beginner in using OM, but I’m using it to derive distorted spectra for an orchestral piece on which I’m working.

When I generate a spectrum with fundamental 55Hz (so A1), distorted as shown (fx^1.25):

the result is as follows:

When, however, I calculate the frequencies manually, I obtain a different set of pitches - for example, the 5th partial (55 x 5^1.25) has a frequency of 411.22Hz, which is close to a G# (415.3Hz), rather than the E natural that OM gives.

I’m deliberately using semitone approximation due to the forces for which this is intended, and I realise that approximating to 1/4, 1/8 etc. would refine this further - but that wouldn’t solve this wide discrepancy.

I’m sure there’s a perfectly rational explanation - as I say, I’d be very grateful if somebody would set me straight.

I’m planning on signing up for the Introduction to OpenMusic course very soon…!

All the best,

Phil