I was at History concert in Dublin, Ireland in July 1997 and I was also at the MJ and Friends concert in Munich in 1999.
They were very different concerts.
The History concert was a full almost 2 hour performance by Michael.
The MJ and Friends concert in Munich was more like an all day festival. It was originally meant to be two concerts, one which had classical music artists and one which had pop and modern artists, but they combined the two ideas and just had one all day concert.
It started about 2pm and there were many different people performing. Some did one song, some did a few. Some were international, some were just known in Germany.
Michaels part was the last part, late at night and he did about 30 minutes.