If you can’t play a piece by heart, then it’s best to avoid playing it before an audience. That means:
- being able to play without having to concentrate too much on what you are doing, or what is coming next, so that you can really put your whole mind and feeling into the piece;
- playing without fumbling;
- if you have to mentally rehearse it or check sheet music before playing it, in order to refresh your memory, you haven’t practiced it enough. Nevertheless, it is a good idea to practice beforehand on the same day of the gig, as well as mentally rehearsing immediately before the chant, and to have sheet music on hand. Sometimes, you can’t remember the first few notes, and glancing at them on sheet music helps, or writing down the first few notes on a piece of paper. (Incidentally, knowing how to read music is certainly useful!)
- even greater mastery comes with being able to play it with different instruments. Playing it in other ways, e.g. singing it a cappella, playing it with clapping, etc. Playing it at different volumes, tempos, or in different keys helps as well. Also, learning a chant from a recorded piece can be helpful too. Learning it from memory is not a good idea as memory can be wrong, e.g. you might play it in a different key, or play the melody slightly differently.
I played a harmonium in a commemorative all-day meditation at Self-Realization Fellowship Sydney Centre today for Paramahansa Yogananda’s birthday, and played two of the chants pretty poorly, fumbling quite a lot. I started off playing one of the chants in a different key (it was four semitones too low), and somehow managed to fumble my way through it, albeit missing one of the lines because I tried to play it around the pitch of the original key, and got confused, so just left the line out and kept playing. If you do fumble, it’s important to always try to keep singing and then catch up the playing to be in time with the singing (unless you realise the key is wrong, then it’s probably best to stop and try to play it in the right key). It’s best to give yourself plenty of time to rehearse a piece, if possible, in order to get the playing to the above standard.
If you haven’t nailed the piece, it’s best to have backup pieces to play that you have more or less mastered, or at least know much better. It’s good if some of those backup pieces are simple. If you don’t have any backup pieces and haven’t mastered pieces to be ready to play them before an audience, it’s best to cancel the gig, or find someone else to substitute you. Fumbling your way through a piece isn’t fun for you or the audience.
Finally, if you do happen to make mistakes in a gig, don’t beat yourself up about it, just learn from the experience and move on!