I am a casual fan of David Bowie's work, particularly the period from 1971-83 (Hunky Dory to Let's Dance). The man behind the masks (from dance-pop to piano-driven rock to ambient electronica to hard rock) has always fascinated me, though. I have always wondered what his personality type could be. I've heard types as disparate as ISFP and ENFJ. On my part? I believe that he's an ENTP. I'll use the four Jung ENTP preferences to prove my theory:
Well, as we all know, Bowie is a 'musical chameleon', changing his musical output depending on changing tastes (the declining popularity of glam rock), internal strife (drugs leading him to Berlin with Iggy Pop, resulting in the Berlin trilogy) and even on personal whims. For instance, he moved into Philly soul over the course of two albums (including Diamond Dogs), just before glam rock's popularity declined. He also realised the popularity of dance-pop in the early 1980's and exploited it to gain hiherto unreached commercial success with Let's Dance. He also intermittently planned movies, at least one of which he failed to complete (the Diamond Dogs movie) and also acts in movies as diverse as fantasies (Labyrinth) and period films (The Prestige).
Bowie uses Introverted Thinking, as his auxillary function, to reach logical decisions as to which musical direction he should take next. This is why Bowie is so visionary in his ability to popularise (to varying degrees) and thus rake in either cash, attention, critical acclaim, or all three. Bowie arguably used Introverted Thinking to move to Berlin in the mid-1970's in an effort to escape his drug addiction. He moved there out of principle - the then-underground German krautrock was something he had not yet played with, therefore compelling him to experiment with it, even to the point of influencing Iggy Pop's 1977 releases. He certainly didn't move there for practical reasons; the music he created, while (surprisingly) financially and critically successful, could not match Station to Station commercially. I say this because Bowie could be as commercially calculated as any other musician. The 'Berlin Trilogy' also created music which I would refer to as 'abstract'; much of it consisting of instrumentals, which, to my understanding (I dislike instrumentals), were electronica, ambient and avant-garde.
Despite this being Bowie's teritary function, Bowie's Extraverted Feeling does appear to be well-developed. For instance, in several interviews, he does come across as somewhat affable. This function allows him to justify entertaining and thus stay loyal to his fans, as he has done for over 40 years. He also helped Iggy Pop out when he was struggling financially by re-recording China Girl to considerable commercial success (Bowie's version is also better), allowing Iggy, as a co-writer, to take home a royalty cheque and then rebuild his life.
Bowie's inferior function - and it sometimes shows. Bowie has intermittenly shown a lack of awareness of musical norms during different time periods (i.e - releasing electronica and avant-garde albums during the punk era). He also released albums with 'Tin Machine' during a time where the worlds of hair metal and then grunge held sway. He also only reflects on the past when prodded and keeps changing his account of what occured, particularly with his bisexuality. A dominant Si, conversely, would use the present to evoke what was with precision (like my mother does). However, Bowie has often acknowledged musical norms, releasing glam rock and Phily soul when those two genres were commercially viable. So, his Si isn't as badly developed as it could be.
In summary, then, I believe that David Bowie is a fairly well-developed ENTP, except during those periods when he fell into drug abuse. Visionary, influental...yep, that's Bowie for ya!