When you are playing behind a singer, thats exactly what you do. You are basically conversing with the singer. You are talking back and forth. Sometimes you start the conversation--meaning that sometimes you lead them in to the next part, and sometimes you talk with them, meaning you play right along with what they are singing. The other times, you play behind them, which means, what they just sang, you try your best to imitate what they sang on the piano/organ...its not something you can be taugt...theres not necessarily a certain way to do it, you can develop your own style with this. Just listen to people. Listen to Karen-Clark-Sheards albums. Both of them have good organists on the solo songs...I think twinkie is on the first one...and Ivan Powell is on the second one. well, hope this helps...god bless ya