One rule a musician should adhere to is playing within their means. Temptation exists for growing musicians to impress people with their talent. However, this desire should be met with discipline. There is a balance between technicality and musical purpose. Going beyond your personal comfort zone could have a negative impact on the song and your potential listener.
There are a couple anagrams in the music world that speak to this:
K.I.S.S. – Keep It Simple, Stupid
L.O.V.E. – Leave Out Virtually Everything
Some of the most successful albums in the world adhere to this philosophy. However, this approach does not necessarily translate into boring music. Those who wish to add extra ear candy should do it gracefully and not risk jeopardizing the accompaniment. A fitting analogy would be freestyle motocross; if a performer tries to pull off a stunt that is way beyond their skill level, they will crash in front of everybody. These stunts should only be revealed to the public after the performer works out all the kinks behind closed doors.
Flashy musicianship is a double-edged sword. While it may impress people in musical circles, it bears little or no relevance to the majority of the population. It’s imperative to keep this in mind when writing music. Besides, this sort of playing should be left to those who have the ability to transition seamlessly into the next part. Failure to do so will become a detriment to everyone involved, including your audience. You would not want to choke in front of others because you bit off more than you could chew.