Thanks Noel.
The style file is Funkwalk and the name is Funkwalk - Ev. 16th Funk. It is primarily MIDI with the exception of the Real Drums style. Hence, the reason why I only heard drums after generating the track a couple of times. The MIDI files won't come back.
First try loading the pgmusic demosong for that style from inside the stylepicker, find out if you can hear all the parts on that songfile. If you can, then suspect a corrupted songfile in yours. The only answer I know to that one is to hit New and reenter the song again. If the demosong does not play its MIDI as well, try another all-MIDI style and see if you can hear the MIDI from that demosong. If not, try the things below.
If it is a case where the MIDI is there after Gen/Play (look at the notation for the parts to see) but you cannot hear the MIDI play, only hear the RealDrums, it might be the case where you don't have a MIDI synth selected and active. Typically that would be the "Use DXi" checkbox in the MIDI/Audio output window.
If it is a case of the above and you've tried selecting MIDi synth again but still no joy, it might be a case where something in the volatile file in the bb folder has become corrupted. Try, under the BB Options menu, "Return to Factory Settings" and select the 2nd choice there, which not only rewrites that file, but also re-invokes the MIDI/Audio Wizard.
--Mac