When faced with a new piece of music – a tune, or a song for example, many of us will just “start at the beginning and see what happens“. Inevitably, after a few bars we will make a mistake and stop, and try again, starting from the beginning. We may continue to stumble at the same point, and just keep repeating the exercise until we get over what ever was causing us to make a mistake, and then carry on until we hit the next problem area. Eventually, after a lot of time, we might end up being able to get to the end without any problem, but may find that certain sections always feel uncomfortable and we don’t play them with the same degree of conviction.
The reason for this is that we have ended up practicing the beginning section of the piece a lot, where as the parts that cause the problem, and the ending in particular have only been practiced a few times. We haven’t really practice the piece as a whole in an efficient manner.
The key is to break the piece into sections and practice those in isolation. There are several ways of doing this. One method is to chop the piece up into (for example) two bar sections, and just practice those separate before eventually combining them. Another approach is to identify the difficult sections and work on those first. What I will quite often to is to try and play through the piece once, sight reading it, and make a note of the sections that I find difficult, but without, repeatedly restarting from the beginning. Once I have done that, and identified the difficult sections, I work on them in the following way.
Practicing a Section
The metronome is key to effective practicing (see How to use a metronome). Set it really slow and then play through the section. If you can’t manage it without making a mistake, go even slower. Also ask yourself whether the section is too long, and if so, break it down into to separate sections. Once you can do it repeatdly without making an error at that speed, increse the tempo gradually until you can play it