When you want to create MIDI patterns other than by recording or drawing them in, you typically have two options: use the arpeggiators, randomizers, and step sequencers found in most DAWs, or build your own pattern generators in applications such as Cycling ''74 Max/MSP. U&I Software Xx 5.2 (Mac, $99) offers a powerful alternative by providing a host of graphical tools to build complex note patterns. Some tools are completely rule-based and others include random elements. Many of the tools can generate both monophonic (all notes on one track) and polyphonic parts—you have 24 tracks to play with—and you can limit the notes on any track to a selected key and mode. You can play your creations using the Mac''s generic GM synth, Xx''s complement of very creative and fully programmable synths from U&I''s flagship software MetaSynth, or your favorite AU plug-ins (with some limitations). Using Xx is not exactly a no-brainer, but it bears a strong resemblance to a standard piano-roll MIDI editor. Once you''ve mastered a few nonstandard techniques, you''ll find it easy to use. Best of all, you can export your creations as either audio or MIDI files for use in your DAW.
You can enter and add notes to an Xx project in three ways: play them from a MIDI or computer keyboard, draw them in using one of 11 tools, or use Xx''s Multi Generator, a 3-track step sequencer with a twist. The tools let you enter single notes, chords, random note clusters, two- and three-part canons, predefined patterns (you can add your own), and multimeasure/multitrack patterns derived from statistical parameters you set. That last tool, the Random Generator, is context sensitive—its action depends on where you click and the notes already present. The Multi Generator is especially useful for creating drum parts (see Web Clip 1). You get separate bar charts for pitch and velocity for each of its three tracks. You can generate bars randomly or draw them in, and you can set each track''s number of steps and scale its tempo. Using different numbers of steps lets you generate long, non-repeating patterns—for example, it takes 42 measures for 3, 7, and 8-beat sequences to repeat.