Hello Dikki
The reason modern arrangers have difficulty playing many songs with 1 rhythm is because the backing is too sophisticated, fortunately most manufactures have now realised this so they now either allow parts of the backing to be turned off, or variation 1 and/or 2 to provide a more simple backing. (Sometimes both)
As to a swing knob I am not sure what you mean, but coming from an organ background, I always found the artists created the swing themselves, while sometimes adjusting the tempo. (I have posted a couple of links below which was recorded in the eighties, the video quality is not brilliant as cameras were less sophisticated in those days)
Enjoy whatever you play

Bill
http://rapidshare.com/files/97434/franz_spectra_swing.ram.html
http://rapidshare.com/files/98415/franz_spectra.ram.html


[This message has been edited by abacus (edited 10-20-2006).]