What Yamaha is describing in "Phrase factory" are the arps and preset drum loop phrases from the pattern sequencer. Some of the arps respond in a way similar to playing a left hand chord on an arranger, while others are dependant upon the actual notes that you play and the order and that they are played. A third type are set drum patterns that don't change no matter what note is played.

It's a different approach than an arranger, and you won't get full arrangements with variations, intros, and fills, etc, but it does allow the composer to mix and match parts quickly and up to 5 arp patterns can be stored and memorized so that they can be changed on the fly during real time play / recording. Also, many of the phrases sound more "musical" than arranger style parts because they aren't necessarily locked into the same pattern, especially those that are controlled via the order of the notes played ( non chord recognition arps ), Also, the assignable knobs can control several parameters in real time including gate time and groove time.

Yes, I use the factory preset stuff, but I also make some modifications to a particular arp so that I have subtle variations within. It's easy to modify and save arps as user arps, or make new ones up from scratch. The remix feature can be very helpful too and looks like it would lend itself particularly well to electronic and dance type creations.

AJ