Ive seen some musicans around town playing solo and use MIDI files as there backup band. Ive searched and cant find anything can anyone shed some light or direct me to a website.

Take a look at www.tweakheadz.com.

Basically, you can use virtual instruments and MIDI files to make your backing music. You'd create the MIDI files in a sequencer such as Reaper or Cubase, then assign virtual instruments to the MIDI files to generate sounds.
There is poetry in despair.
Sonar 8 has some great virtual instruments so if you need a sequencer thats a nice way to go IMO.

version 7, (what I use) is also good but lacks that piano VSTi which is a nice add. Check out the song "Into The Stars" in my UG Profile. I made that whole song in Sonar 7 Producer using MIDI and Sonar's VSTis.