What goes in the mind of a musician while he or she is improvising? Hard question to tackle, but without further adieu, here's a post entitled Thoughts While Improvising. Keep in mind that these are taken from my point of view. For other musicians it might be a lot different. They could be thinking about cheeseburgers. First, I'm always thinking about the melody, the chords, and certain scales or motifs that work within that system. I always look at the song and keep the melody, chords, and scales in my mind's eye, so to speak, so that when I need to take a solo after my band mates, I don't have to focus on any of that stuff as much. Rather, it's ingrained in my head through repetition; of hearing the song a million times, hearing other people play the song, hearing my band play the song before, hearing my band mates play their solo and adjusting to it when I go, and hearing the familiar chord progression and melodies. The easy way of explaining it is that you have to study the song [the chords, the melodies, the rhythms, the comping, the lead work] before you can truly know the song, and then after you've done that, you can throw it away, and go to the next stage.
Second, there are always those type of musicians who don't have to study songs to improvise well. Perhaps they're just natural good musicians and can improvise on a muddy boot some amazing rhythms. This is the part where if you know all the meat and potatoes of the song [the structure, the chords, the melodies], if you're comfortable enough and have enough practice, you can actually just throw all that stuff out the window, and, gasp[!], just play straight from the heart. This is more of a bluesy [and rock] feel rather than a straight ahead jazz approach [at least imo] but it gets the job done. This style of improvisation, when I play like this, I don't think about anything at all in particular, rather, my playing ebbs and flows through my inner feelings, my inner emotions. I believe that this is true jazz improvisation, but sometimes you have to study the song in order to get here [I prefer to study the songs].
Third, I think about the main theme of the song. What's the main melody? Remember to always keep that in mind even if you're going far over the moon in a modern straight ahead jazz guitar solo [think Mike Moreno, Lage Lund, Mary Halvorson]. If you keep playing the melody, add permutations to it, and add that as part of your solo, it gives your solo a lot of structure and weight. Sometimes I think about the melody, and come back to it, either at the end of the song repeating the head, or just ending the song in an interesting way, using the melody to form an unusual [b9, #11, 13th note chords] but great sounding chord[s] to end on.
Lastly, improvisational music is a spiritual endeavor. One of the magical things about playing a form of music that is based on improvisation [jazz] is that when you improvise, there's no telling where you're going in your head. You're sitting on a chair but metaphysically speaking, you could be flying across the heavens. For me, it feels as if time itself has ceased to exist, and all my thoughts have ceased to exist, and I'm in some sort of black hole, blacked out from the rest of the world and others, even when people see me play on a stage [although I feel them and their feelings too], I feel this inward prescience, the cosmic energies that arise out of me and into the world, the world-hood of the world, a sort of being and time, daesein, if you will.
Improvisation brings me to a spiritual plane where nothing can hurt you, you're invincible, you can fuck up and make mistakes but it won't hinder you or hurt you in the long run, it forces you to adapt to any and new situations, teaches you how to play in an ensemble with others, how to comp [accompany, strum chords for the band] for other musicians, how to take solos, how to play melodies with confidence and ease. When you see that this is all part of the vast history of American jazz you can see how your playing has been influenced by history, and you can take solace in the fact that you are keeping the tradition alive through your music, however you choose to do it. There's really nothing quite like it. Even though I love rock and roll, there's something about jazz, about improvisational music, that can't be forgotten, that can't be broken, it's still untouched, perfected by time, and the great performers that played it.
There's no right or wrong way to think while improvising. Most of the time I feel like I'm not thinking at all, rather that I'm feeling the music in a much more visceral way. Sometimes you get so used to just playing from the gut, that eventually everything you play comes from that same place, where you're playing more off your own feelings rather than the song or the song's structure. Whatever works is fine. Finding your muse is what takes a long time when it comes to improvisation. Find what works for you. One thing I didn't mention is that sometimes when you're doing improv, you have to think about what you're going to play ahead of the time. Things like that. Who knows, for some people, thinking about cheeseburgers might encourage them to play a lot better. For others, much less so.
