a general voice editing question

I’m listening to some amatuer singers lately from around the web, and I’m noticing some pretty crazy octave ranges in a couple singers, and it got me curious…

could these singers be touching up their range with some ingenious singing and a bit of pitching up? How difficult is it to determine if a voice has been pitched up several semitones or even an octave? How detectable is it with free or cheaply available software? I’m going on the assumption that these singers don’t pirate their audio software, but I imagine there are some good enough tools that are open source like audacity to accomplish it.

Small amounts of pitch shifting (a semi-tone or so) are quite easy to do in Audacity and the quality is pretty good. Larger changes tend to cause the quality to suffer quite badly. There are some (expensive) tools (such as “Autotune”) that will do a better job with larger pitch shifts, but it is still difficult to make it sound natural.

It’s a cousin to the problem of sampling for a digital keyboard. You don’t need to sample all the keys, you just need one about every three notes and do pitch shifting from there.

Even at that, you can usually hear it working. Between the magic two jump keys it sounds like a slightly different piano. So no, it’s not easy to do well.