TC-Helicon is shipping its Harmony4 plug-in for Digidesign Pro Tools | HD ($995). According to the manufacturer, Harmony4 can be used to generate one- to four-part harmonies, fatten existing harmony tracks, and create vocal special effects. The Pro Tools | HD version of Harmony4 supports Universal Binary and Windows XP, and runs on Venue.
You can use Harmony4 to create up to four virtual singers with individual gender, vibrato, levels, and various humanization controls, all from a single vocal track. The plug-in's interface lets you choose your desired harmony, such as automatic scale-based harmony that follows melismatic singing, or MIDI note control that allows any melody to complement the lead vocal.
The TC-Helicon harmony algorithms in Harmony4 are also available in VoicePro, VoiceLive, and VoiceWorks.