One of the problems with digital audio is that it is not as pliable as MIDI data with respect to tempo and pitch. Most software solutions result in compromised audio that contains artifacts of the pitch-shifting or time-stretching process. Audio Genetics' Alkali ($299) offers a different approach to the process.
Alkali slices your audio loops into discrete components. When tempos change, it moves the components farther apart or closer together, as the tempo requires, rather than stretching the entire audio event. In this way, loop components can be quantized, individual elements can be pitch-shifted, and you can even get a straight feel to swing.
A Tempo slider at the left of the screen lets you "varispeed" the loop to taste, while additional sliders let you adjust the pitch without changing tempo, quantize, adjust quantization percentage, and add swing.
The program supports DirectConnect and appears as a plug-in in Pro Tools 5.0. When you find the settings you like, the file is spotted directly in a Pro Tools track. Because Alkali can render grooves as Sound Designer ll files, you can use your Alkali-created grooves in other digital audio sequencers.
Alkali supports REX, Sound Designer ll, and AIFF file formats. The program is bundled with a library of REX files on CD-ROM. You will need a PPC 603 and Mac OS 8.61.