Hi Davey,
I don't think that there are any 50's rock and roll bass styles in realtracks format. There are a few boogie realtrack styles and you may find something useful among them. Other than that it is probably worth trawling the BIAB midi styles for suitable bass lines (I can't see an obviously suitably titled style set so you may need to rummage through the 'Requested' style sets). I think that Notes Norton may sell some Rock and Roll Styles as well so worth checking out his website.

Happy hunting!

Regards, Aubrey


If I hadn't seen such riches I could live with being poor.