Graham,

Check out the JAZSIMP Midi style. Very simple bass line in both A/B sections. I use this bass part in all of my swing songs.

As far as RT vs Midi bass, I tend to agree with poster that said the audience (for the most part) does not hear or care about the difference. I tried a RT bass in a song at a gig and found that my ears were used to the Midi bass line - simple yet solid. The RT bass often danced around the root at a time when I didn't expect it. Did the audience notice? Probably not directly but I'm sure they felt something different in that song. With the ambient lounge noise, having that solid simple bottom present is key. I'll play around with the 'new' Very Simple RTs, but in the meantime will stick with Midi at gigs. I do use RT Nylon Guitar in my Bossa songs.

...and I'd love not to take BIAB to a gig if they would pay for a bass player and drummer.

R