John: I'm sure you will enjoy the harmonizer. I have a question for you or anyone else about using one of these with BIAB and or RB. Since I play bass on a gig or @ home, this is less than ideal to guide the MUS IQ.. My unit is a Digitech Vocalist Live 4. It works good enough for me with rhythm guitar. With a bass guitar the root note will select a chord change. Western swing requires switching to 4/4 mid song sometimes. Now we have usually 1-3-5-3 or 1-1-6-3-5 etc. NOT GOOD. My O.S. is Windows 7-64. I have an HP Pavilon dv7. lap top, 6GB of ram / 750 gb hd with intel CORE I-7 processor. I use the 1/8th ear phone out to an Allen&Heath ZED 10FX mixer. Present routing is: BB to Mixer stero ST2 in,- vocal mike to mixer--aux.1(mike channel-selective with send knob)- send to line in lef/mono of the Vocalist 4. Bass guitar 1/4 out to guitar in of the Vocalist 4--then guitar thru to bass amp. Step on a pedal and the wet harmony signal only goes to ST1 channel of the mixer. I almost never plug the mike into the Vocalists 4. The mixer has musch better pre. amps. and better E.Q. A third up and a third down fits most of the songs I sing. With this set up I can offer harmony to others when desired. By zeroing my vocal channel send and opening another, the Vocalist 4 can be used by others in the band. What I would like to do is send a RB or BB clean rhythm guitar track to trigger the Vocalist 4 instead of my bass signal. Panning the BB guitar signal full left or full right has not worked very well so far. Too much bleed from drums soloists etc. Also everything else has to be pannsd to the oppisite out. That sucks big time I am thinking that an external usb unit would solve this routeing problem for me. What would I need and how much money? I am open to suggestions. e.l.c.