When you are a professional you need to prepare rather than practice. Before playing new songs, figure out what you need for each particular song and then get ready for it accordingly; if there are tricky runs mark in fingerings, if it's a tricky rhythm mark the beats clearly, and if the harmonies are more unexpected, then actually play through the song, etc. The most important is to anticipate what mistakes you would make more than playing the piece again and again.
Professional musicians need to accept the difference between practice and preparation. Preparing means that many times you will be ready enough to do a good job, but that it won't always be the best that you could have done if you had had time to practice. At the end of the day the options are either practice to perfection and don't make a living out of your perfect pieces, or prepare efficiently and play a bit under your ability but go from gig to gig.
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Posted by Geraldine at 10:24 PM