So a normal practice session is 60/40 technique-theory to songs. But as we approach a single performance we will adjust our practicing schedule. NOTE: as a musician becomes better and better, performing pieces, even amazing pieces, becomes easier and easier. Excellent musicians will need to adjust their schedules only slightly (if at all) for performances, as their skill level easily includes performing difficult pieces in public. You adjust your practice to the degree the pieces you play and performing itself seem difficult and a challenge. OK, so as you come close to the performance, you should spend more and more of your time performing your piece(s) and less on technique and theory. Remember we made the comparison of technique and theory with research and development and performing songs with production and distribution. As the performance gets closer, quit working so much on research and more on theproduct soon to be released in your concert. To the point sometimes you are only playing enough exercises to warm up and then get to your songs. This is OK as long as this is only a season in your musical journey as you approach an important performance, not the new standard for your musical practice. You'll go back to 60/40 in a few weeks. NOTE the second - MANY professionals quit growing as they become successful and are performing more and more. Their practice becomes simply a time to work on songs and they are no longer breaking new ground or growing in their musicianship. And I'm saying that's a real challenge to not do that. The most dedicated professionals struggle to find progressive practice time when they're touring or gigging.
Technique, exercises, theory, ear-training are investing in the future. Performing pieces is the present. Future and present are necessary.