A good martial artist is one who has trained to the point that his reaction time in response to an attack is quick and decisive. His endless hours of practice and the honing of his abilities and reflexes are so that he can effectively utilize them when the time demands it.
As musicians, we must also prepare for quickly responding to the moment. We must develop our musical reflexes so that we can effectively participate during a musical performance. This is especially vital when playing in an improvisational setting, where you need to instantaneously react to what your bandmates are playing.
Preparation is simply practicing in order to reach a high level of proficiency in which your mind and body work perfectly together. This level or proficiency allows us to function in a musical situation both comfortably and confidently. It means being able to play effortlessly without struggling to keep up or getting lost. Some call this state “playing in the zone,” or the “creative flow.” It is the place where it seems like you can do no wrong, and everything is illuminated so to speak.
In order to maximize our ability to generate this state of performance, we need to train our musical reflexes to be quick and decisive just like a martial artist’s. There are three stages to our musical reflexes that must be seamlessly coordinated to give us a quick reaction time in making a musical response. We need to perceive what is being played, process this information, then perform accordingly. The following diagram illustrates this concept:

First, we must detect the stimulus to which we will respond. This means listening to what everyone else in the band is doing. Is the drummer changing to a half time feel for the chorus? Can you hear the various chord changes and modulations that the other rhythm players are playing? You must develop your ears to be sensitive to any change. The best way to do this outside of a band situation is to listen to a lot of music, and really focus on what’s happening. I recommend taking a particular song, and listening to it several times in a row. Each time concentrate on a different instrument. What is it doing in relation to the others? Finally, listen to the song as a whole, and hear how everything is working (or not working) together.
The second phase to our musical response is processing the information we just perceived. This is basically being able to interpret exactly what is going on. We develop our ability to understand what we perceive by learning to recognize patterns. This is typically referred to as ear training, and there are a lot of courses available to help you develop this skill. I recommend the Jamey Abersold Ear Training Course.
The last phase is in actually performing your response. This is obviously having the physical technique to play something. You fingers must be able to accurately play the chords or notes clearly and in time with the rest of the music. This is the reason behind practicing all those tedious scales, and chord progressions on your own at home. This is the equivalent of a martial artist practicing front kicks over and over in order to gain strength, speed, and accuracy.The three factors of creating an effective musical response can be isolated and worked on individually, but you must also practice utilizing them together. This is where you throw yourself into the deep end of the pool, and either sink or swim. Start by randomly choosing a song you don’t know, and try to play along with it. Don’t try to figure out each guitar part, just attempt to contribute to the song in some way. Figure out the key, and experiment with scales, rhythms, and whatever techniques you’ve been practicing. Pick a new song each time your practice.Once you’ve gained some experience in the practice room, throw yourself into a band situation where everyone knows the song but you. This is where it can really be scary and intimidating, but you will really shock your musical reflexes into adapting and responding at a whole new level. Over time your ability to quickly and accurately respond will become second nature. Apply yourself to developing your musical reflexes, and practice hard, play harder.