humm...right click..then "change settings" something like that.
Quote by Slicendice

stop using UG as a search engine.

I guarantee that google will be 10x more helpfull and loving.
on the Sound tab, there is a music sign is the Tempo. Just click it and change the characters.
Right click on the first chord/note of the measure, and select mix table. Then the bottom checkbox is tempo. Set the tempo you want.