You can find a lot of sample spinning workout routines online, complete with suggested music. For example, one workout calls for 6 minutes of seated flat warmup, followed by 3 minutes of standing run, 1 minute of recovery, 15 second seated sprints for 3 minutes, 3 minutes of jumps, 1 minute of recovery, 6 minutes of seated and standing climbs, 3 minutes of 30 second seated sprints, 4 minutes of seated flat, 4 minutes of standing climb, 3 minutes of seated climb, 4 minutes of seated flat, and 4 minutes of cool down. Of course if you are part of a class, you have to go with what the instructor has planned, but if you have your own spinner bike you can do whatever you want that suits your training mood.
The real trick to burning fat is the variety built into these routines, forcing your body to constantly work, rest, and adjust to different stress loads. By incorporating some cycling and spinning into your workout routine, you avoid the boredom that eventually sets in when you always do the same thing. But spinning is not for everyone. Men in particular tend to be less comfortable sitting on the saddle for extended periods of time – so give it a try and see if you like it!