Thank you very much for the detailed answer, Cherry ! Well, as a **** rookie I may be a bit naive still. I am surprised that there is so much left to learn !

Yesterevening I tried out some very simple procedures : Using Notation Composer to change the tempi of the movements of a MIDI version of Mozart KV 576 piano sonata and then playing this modified version with SynthFont. In this case no problem : Export MIDI from Composer, then open MIDI with SynthFont. Seems to work fine, while there were many disturbing and unexpected effects to overcome. F.i., there is a delay of some seconds when you take up the replay in Notation Composer somewhere in the middle. Only when you start at the beginning of a piece the opening is as it should be. Thus after any break the playback should be held back until the setup is ready. This is a minor glitch of the Composer software to be corrected. Thus I am crawling along. Seems there is no short track for anybody.

And I have a remark to add on this forum : There are some answers of you to other participants that are of interest for me. But to get back at those answers I have to write down the details. It would be much easier to save the date and time of some entry and using this to get back to the point of interest next time. F.i. your original posting starting this thread was of "03-08-2010 02:45 PM". But I can't use it to get back at this, I have to know where to go. When the number of entries on this forum expands, it becomes more and more difficult to find the way back to some posting of interest. Could this be changed ? It is almost impossible to have two entries with exactly the same date and time, so it is a pretty sure method to find some posting later on.

Cheers from Hubertus