Hello everybody, im playing "billie jean" by Michael Jackson in my band, and im playing the main bass riff. But the problem is that everytime i had played the riff a few times, my fingers start to cramp. And i cant really do anything else than stop playing and start again when my fingers feel better. But do you have any ideas to what i can do so my fingers dosent cramp so much? Any tricks or any thing? Im open to it all.