Frank,

Most drumsets in Yamaha styles are in bank 127. De different sets defined by the patchnummer are all compatible with the standard kit (bank 127, patch 0). The standard way in OMB to handle this in GM mode is to mute any drum event outside the GM range (35 - 81). I'm not sure that you get a better result by converting the notes to anything simular inside the GM range. But anyway if you have a conversion table for the standard kit then you could use the same table for all the other drumsets in bank 127.

Sometimes you might also find drumsets in bank 126. You will need the synthesizer that produce these sounds to find out if there is any similar sound in the standard kit.

And then there are styles converted from non-Yamaha keyboards that sometimes contain drumsets that are not compatible and can be in any drumbank.

The most problems where with the Arabic styles and they can be converted with the comversion table "bongos and congas".

If you find any style with imcompatible drum notes just discard it or import a drumtrack from another style.

Cheers

Jos