This plugin gives you the opportunity to change the pitch of individual tracks or full mixes, in the range of plus/minus one octave. Audio length (tempo) is not affected by this plugin, since audio is completely resampled. Besides being a special effect for creating foxy guitar tracks, it may come handy if your (otherwise very attractive) singer or chorus-girl was a bit indisposed at the time of recording: with the power of Ardour automation, you are given a chance to correct smaller pitch errors.

source: http://tap-plugins.sourceforge.net/ladspa/pitch.html

Credit: Tom Szilagyi