Hola Ginna! nice to see you here. About your question, as Kent and our forum pals exposed, Band-in-a-Box can only use one synth at a time by itself. It can be a GM synth like VCS you already know and use. But sometimes I also want to remain in the realm of Band-in-a-Box, leaving RealBand for final touch-ups, mixing and other task where it shines with own light. As the most of us already know there are plenty of great MIDI Styles in BiaB, and myself enjoy a lot by combining them with RealTracks! However there is a alternate way for the multi-instrument matter. But before I talk about it, I want to warn you, nothing will substitute or replace RealBand or any other DAW you use, RB is a amazing PGMusic devoted program designed as a multi-timbral big tool able of make near of every audio/MIDI from simple to surgical task you want to do, plus many of the BiaB song construction features. Also, is not my intention to advertise third parties neither I have commercial relationship with them in any form, just I think if out there exist something able of to enhance our BiaB experience in some way, it deserve a mention, and the decision to use it is everyone's free will. Ok, after this remark, the fact is that you are right Ginna, there is a way to make that magic you wish happen! if there is a tool named Chainer XLUtop , a little piece of software that let you load in BiaB all the synths and VST/DX efx plugins you want and your PC system power and speed allow. I bought it with the intention of convert my Laptop in an portable instrument/efx rack since Chainer is a standalone program, but it also load as a VSTi or VST plugin in BiaB VSX/DXi synth slot! and in my case at least, working like a dream. Once loaded, you can set any separate or combinations of VSTi/DXi instruments you want. For example, you can have Kontakt Player with an sampled acoustic piano and strings, Trilogy with bass and EzDrummer, in three separate Chainer slots while there also are VCS, Coyote and Edirol Hyper Canvas sharing another slot, all three playing MIDI instruments data from BIAB at the same time and each with its own MIDI channel and independent control.

Furtherly you can route any instrument you want to any other free Chainer slot and process them with efx plugins like compressors, EQ, Chorus, reverb, etc, including all the PG VST/dx effects bundled with BiaB. There are Mute, Pan, Transpose, CC, automatization and a random patch creator for loaded synths and many more features. 100 slots in ten internal mini-racks are available, plus Chainer is able to load into itself for crazy infinite number of slots. As an idea , I use to load 3 (or more) GM synths for the sake of compare each one to other, but since you can use all at same time, you could to obtain impressive rich sound and layered textures result of the sum of each module audio outputs. I know there are some others “virtual racks” like Steinberg one, but I think it is discontinued.
As sample I included two screen captures and a demo BiaB song I rendered using at least 5 different high quality VSTi instruments + effects loaded in Chainer and one RealTrack sax.

First screen-capture show BiaB and three different GM VST modules, included VSC, you can play them separate, all three at same time or selected MIDI tracks in each one. Note there is PG Five Bands EQ in the next efx slot.
Second screen-capture show an advanced multitimbral setup with some high end synths and sampler based instruments ALL loaded in Chainer and playing in BIAB. VCS still there as visual and audio reference and even you can add its sound palette to midi instrumentation if you want.

I hope this help you Ginna

Saludos

Carlos

PS: are you in town this week Ginna? if yes, let me know or phone me. We miss you last month in M-Audio clinic, I introduced Band-in-Box there, we exposed to audience how Band-in-a-Box in plug-in mode can “drop” RealTracks and MIDI instruments to Pro-Tools. The wow factor flooded the room, hehe .

Gabriel Arellano,
Nucleox Music