As someone who likes to explore different styles in his illustration work, I have the utmost respect and admiration for a musician like David Bowie who manages to explore, experiment and evolve in his music during a career that has spanned five decades! So put me down as a big fan of the man and his music.
This was done for the current David Bowie jam over at The Drawing Board.
The 'painting' started out as a blue ballpoint pen scribble. It was then scanned into Photoshop and with the line colourised on a multiply layer, colour and shading was added using a hard brush with opacity jitter set to pen pressure (this creates transparent to opaque brushstrokes depending on how hard you press. Good for painterly brushstrokes). Then I went to Painter and blended together the line and shading to create a painted look (see my paperboy tutorial for that process in detail). Then it was back into Photoshop where I added detail with the aforementioned hard opacity brush. Noise was added at the end to give it a slight grain, reducing the digital look.
Here's a close up of the face detail