One of the most significant items added to Digital Performer 4.6 was the Pitch Automation feature, which allows you to draw in anything from subtle pitch correction to extreme transposition. For the most successful results using Pitch Automation, you should understand that Digital Performer employs two different pitch-shifting algorithms, each of which produces different results. You can select these on a per-soundbite basis in the Soundbites window.

The "PureDSP" algorithm applies formant-corrected pitch shifting, which is what you'll probably want whenever you're touching up a vocal track. It helps maintain the original timbre of the track even when you've transposed pitches. By contrast, the "Standard" pitch-shift algorithm doesn't employ formant correction and is likely to produce the "chipmunk" effect when raising pitches and the "Lurch" effect upon lowering pitch. That doesn't mean you shouldn't use it on your vocal or solo instrument track — try it out and see what it does!

You can specify which algorithm is applied to each soundbite (or lock it to prevent pitch shifting) by opening the Soundbites window, selecting the soundbite, and clicking on the "Info" tab. The "Transpose" box offers the choice of PureDSP, Standard, or no pitch shift. For smoother workflow, open DP's Preferences window and check the "Analyze Soundbites for DSP as soon as possible" item.